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fiSlS'-i, Q i iiiiiiiiliiiiJS© p NEW YORK ACADEMY OF SCIENCES SCIENTIFIC SURVEY OF Porto Rico and theVirgin Islands VOLUME Ill-Part 2 Tertiary Mollusca from the Lares District, Porto Rico— -Be/a Hubbard NEW YORK: Published by the Academy 1929 TERTIARY MOLLUSCA FROM THE LARES DISTRICT, PORTO RICO By Bela Hubbard INTRODUCTION The material here described was collected in making a study of the geology of the Lares District in the summer of 1916, under the auspices of the New York Academy of Sciences and the Insular Government of Porto Rico. The present paper is a part of the report on the geology of the Lares District, the completion of which has been delayed two years by the war. As the section dealing with the general geology and stratigraphy has not yet been completed, the present report, dealing with the Tertiary Palaeontology, is pub- lished in advance. It will be noted under the descriptions of the species, that full use has been made of the material collected by Dr. C. P. Berkey in 1914, by Dr. D. R. Semmes in 1915, and by Dr. A. K. Lobeck in 1916, and in some cases their specimens have been used for illustration. No attempt will be made here to describe the stratigTaphy, but the following tabulation of the subdivisions^ of the Younger Series of the north coast is given in explanation of the horizons referred to under the descriptions of the species. Younger Series San Juan formation (Berkey, 1915) Pleistocene to Recent. UNCONFORMITY / Quebradillas limestone (Berkey, 1915) Arecibo Group I Upper Oligocene (Bowden) \ Los Puertos limestone (Hubbard, 1917) (Arecibo formation I Lpper Oligocene of Berkey, Pepino ] Cibao Limestone (Hubbard, 1917) formation of Hill i Middle Oligocene nnd Vaughan) I Lares formation (Hubbard, 1917) \ Middle Oligocene San Sebastian shale (Berkey, 1915) Middle Oligocene unconformity Older Series (Berkey^ 1915) Cretaceous *These subdivisions were made and described by the writer in a short paper presented before the New York Academy of Sciences, Section of Geology and Mineralogy, in February, '917. 80 SCIENTIFIC SURVEY OF PORTO RICO AcKNOWIiEDGMENTS Acknowledgments are made to Sefior I^arciso Rabell, of San Sebastian for aid in collecting fossils and for the interest which he took in the field work ; to 0. J. Maury for the opportunity of com- paring some of the material with hers; to Miss A. L. Hepburn^ Columbia University Library^ for valuable assistance in securing the many necessary but scattered palaeontological references ; and to Dr. A. W. Grabau for advice and assistance in describing many of the species. FOSSIL LOCALITIES- Field Numbers. 1. Lares road, north side, near K. 38 San Sebastian shale. 7. On the cart road 1.75 miles north-east of Lares. Lares limestone. 8. About 0.5 mile north of No. 7. Lares limestone. 10. About 1 mile north-east of No. 8. Lares limestone. 23. About 5.5 miles north of Lares, and about 2 miles north of Central Soller. Echinoid zone of Cibao limestone. 24. About 6.5 miles north of Lares, on cart road to Camuy, at southern boundary of the belt of pepino hills. Base of Los Puertos limestone. 41. On the cart road to Camuy, 0.25 mile south of the village of Cienega, near the Central Alianza. Quebradillas limestone. 42. On the cart road to Camuy, 0.25 mile north of the Central Alianza. Quebradillas limestone. 52(a). On the cart road to Collazo 1.75 miles south of Quebradillas, and a short distance north-west of the village of San Antonio. Quebradillas limestone. 59. Valley of the Guajataca River, 1 mile south of Planas. Los Puertos limestone. 61. On the upland surface near the valley, and 0.3 mile south of No. 59. Los Puertos limestone. 62. About 0.6 mile south of No. 61, on the lowland just south of the belt of pepino hills. Cibao limestone. 64. About 0.3 mile south of No. 62, on cart road to Collazo. Cibao limestone, 65. On the cart road 2 miles north-east of Collazo. Lares limestone. 72. Lares road at K. 28.6. San Sebastian shale. 74. Lares road at K. 29.3. San Sebastian shale. 75. Lares road at K. 30.4. San Sebastian shale. 76. Lares road at K. 32.9. San Sebastian shale. 83. Collazo Falls section, at top of second falls below the bridge. San Sebastian shale • HUBBARD, TERTIARY M0LLU8CA FROM LARES DISTRICT 81 84. Collazo Palls section, at base of second falls below the bridge. San Sebastian shale. 86. Collazo Falls section, at top of fourth falls below the bridge. San Sebastian shale. 89. Collazo Falls section, below the sixth falls below the bridge, in the lowest horizon exposed in the section. San Sebastian shale. 92. Lares road at K. 28.8, in ledge 12 feet above the road. San Sebastian shale. - 100. Talus at base of the cuesta north of Lares. Lares limestone. 118. On the upland surface 0.25 mile north-west of Lares plaza. San. Sebastian shale. 120. About 180 yards north-west of No. 118. San Sebastian shale. 126. Lares road, near K. 37. San Sebastian shale. 140. Base of the cuesta on west side of the Camuy River valley at the fork of the cart road to Utuado and the new road to Arecibo San Sebastian shale. 142. Cuesta at No. 140, in the limestone cliff overlying the basal shale. Lares limestone. 158. On cart road to Camuy, about 500 yards north-west of K. 19.5 of the new Arecibo-lares road. Cibao limestone. 161. About 500 yards north-west of No. 158, on the same cart road. Cibao limestone. 162. About 600 yards north-west of No. 161, on the same cart road. Echinoid zone, Cibao limestone 165. Near the point of emergence of the subterranean Camuy River. Cibao limestone. 167. A short distance north of No. 165, on the west side of the Camuy River. Cibao limestone. 174, About 0.5 mile north of No. 167, west side of the Camuy River on cart road to Camuy. Los Puertos limestone. 176. About 0.75 mile north of No. 174, on the same road. Los Puertos limestone. 179. About 0.4 mile north of No. 176, on the same road. Los Puertos limestone. 182. About 0.6 mile northwest of No. 179, and about 0.5 mile south of the ford where the cart road crosses to the east side of the Camuy River. Los Puertos limestone. 191. On the automobile road between Camuy and Quebradillas, near K. 40.5. Quebradillas limestone. 192. On the same automobile road, near K. 40. Quebradillas limestone. '98. On the automobile road west of Quebradillas, near K. 28.7. Quebradillas limestone. -04. Sea cliffs at the east mouth of the American Railroad tunnel at the mouth of the Guajataca River, north coast. Quebradillas limestone. 82 SCIENTIFIC SURVEY OF PORTO RICO 205. In the railroad cut 80 yards west of the railroad bridge over the Guajataca River, and 450 yards east from the automobile road grade crossing. Quebradillas limestone. 209. Guajataca River valley, west of the village of San Antonio. Quebradillas limestone. 216. About 1.75 miles south of K. 14.7 (Isabela-Aguadilla automobile road). on cart road near Arenales bajos. , Quebradillas limestone. 217. Nearly 0,5 mile south of No. 216. Quebradillas limestone. 220. Near Arenales altos, about 2.5 miles south of No. 217, and 150 yards east of the cart road. Los Puertos limestone. 225. On the cart road near Robles, 25 feet below the summit of the cuesta. Top of the Lares limestone. 226. Zone about 90 feet below No. 225. Lares limestone. 227. A 40 foot exposure of marl on the cart road south of No. 226, and 250 feet below the summit of the cuesta. Lares limestone. 229. About 1 mile north of K. 17.5 (Lares road), on cart road near Hato arriba. Base of Lares limestone. 230. A short distance south of No. 229, and about 50 feet lower in elevation. Top of San Sebastian shale. 231. About 100 yards south of No. 230, at a slightly lower elevation. Coral zone of upper San Sebastian shale. 232. About 200 yards south of No, 231, and 1,350 yards north of K, 17.5 (Lares road), at an approximate elevation of 180 feet above the road. A five foot exposure of marl marking the dementia dariena zone, San Sebastian shale. 232(b). A fifteen foot exposure immediately overlying No. 232, and remarkable for the abundance of Turritella tornata. San Sebastian shale. 233. On a small secondary cuesta a short distance south of No. 232. San Sebastian shale. 234. South of No. 233 on the same cuesta. San Sebastian shale. 235. South of No. 234, and 1,050 yards north of K. 17.5 (Lares road) at an elevation of 180 feet above the road. San Sebastian shale. 236. South of No. 235, and 900 yards north of K. 17.5. San Sebastian shale. 237. South of No. 236, and 820 yards north of K, 17.5, at an elevation of 100 feet above the road. San Sebastian shale. 244, On the cart road to Camuy, 1 mile north-east of Lares, in limestone quarry near summit of the cuesta. Lares limestone. 254-5-6. Talus from the cuesta north of Lares. Taken from the road along the Guajataca River, about 0.75 mile north of Lares plaza. Lares limestone. 2G1. Collazo Falls section, at base of second falls below the bridge, an<l overlying No. 84. San Sebastian shale. 262. Collazo Falls section, at top of third falls below the bridge. San Sebastian shale HUBBARD, TERTIARY MOLLUSGA FROM LARES DISTRICT 83 263. Collazo Falls section, half way between top and bottom of the fourth falls below the bridge. San Sebastian shale. 264. Collazo Palls section, immediately underlying No. 263. San Sebastian shale. 265. Collazo Falls section, at base of the fourth falls below the bridge. San Sebastian shale. 267. Collazo Falls section, near the base of the section, overlying No. 89. San Sebastian shale. 268. Collazo Falls section, in the red sandstone at the sixth falls below the bridge, and overlying No. 267. San Sebastian shale. 280. About 880 yards north of Moca on cart road. Lares formation, shale facies. 281. About 1,100 yards north of Moca on cart road. Lares formation, shale facies. 282. About 1,150 yards north of Moca on cart road. Lares formation, shale facies. 287. About 1.25 miles north on Moca on cart road. Top of the Cibao limestone. 313. Sea cliff 0.75 mile northeast of the Point Borinquen Light House, from a stratum 55 feet above sea level. Quebradillas limestone. 314. The same cliff, in a stratum 10 feet above sea level. Quebradillas limestone. 317. About 1.25 miles north of K. 2 (Aquadilla-lsabela automobile road), on cart road, 350 yards north of the American Railroad grade crossing. Quebradillas limestone. 318. A short distance south of No. 317, in railroad cut, about 200 yards north- east of grade crossing. Quebradillas limestone. 319. In quarry east of cart road, and about 0.6 mile north of K. 2 (Aguadilla- Isabela road). Quebradillas limestone. 324. Small limestone outlier about 300 yards south of K. 1.7 (Lares road). Lares limestone. 330. Southwest of bridge over Culebrines River near K. 2 ( Aguadilla-Aguada automobile road). Lares limestone. 331. Aguadilla-Aguada road, south of sugar railroad crossing near K. 2. Lares limestone. 332. Same road, about 300 yards southwest of No. 331. Lares limestone. :533. On automobile road to Rincon, 1,150 yards west of Aguada. Exposure on north side of road. Lares limestone. 334. Same road, 100 yards west of No. 333. Lares limestone. >3.j. Same road, 290 yards west ot No. 334. Laies limestone. 343. Same road, 640 yards northeast of bridge over the Rio Grande. Lares limestone. »44. Same road, south of No. 343, and 460 yards north of bridge over the Rio Grande. Lares limestone. 84 SCIENTIFIC SURVEY OF PORTO RICO 370. Exposure in sea cliff on south side of the American Railroad track at Point Jiguero, 930 yards northeast of the lighthouse. The San Juan formation may be seen here, plastered on the Tertiary limestone. Lares limestone. 616. Uppermost stratum in quarry 0.5 mile south-east of Auguada, on south side of road, and northeast of the American Railroad grade crossing. Lares limestone. 619. Same as No.* 616, but from lowest exposure in the quarry. Lares limestone. 621. Exposure on south side of railroad tracks, about 580 yards south-east of the Aguada railroad station. Lares limestone. 664. East side of Camuy River valley, 2.25 miles southeast of Camuy. Quebradillas limestone. 670. East side of Camuy River valley, 1 mile southeast of No. 664. Quebradillas limestone. 671. Same locality as No. 670, but from a stratum a few feet above the latter. Quebradillas limestone. 678. East side of Camuy River valley, about 1.5 miles due south of No. 671, and about 0.75 mile north of No. 182. Quebradillas limestone. 749(a). On cart road, about 0.5 mile north of bridge at CoUazo. Lares limestone. 757. One mile northeast of Lares, on the cuesta, in quarry near No. 244. Lares limestone. 758. Same locality as No. 757, but at a slightly higher horizon. Lares limestone. 800. About 100 yards south-east of No. 24. Top of Cibao limestone. 801. In railroad cut at east end of railroad bridge over the Guajataca River, north coast. This locality is about 50 yards east of No. 205. Quebradillas limestone. The following localities are recorded from field notes of Dr. C. P. Berkey. 10. North of the military road in the vicinity of Carolina. Quebradillas limestone. 77. Military road 1.5 kilometers west of Ponce. Upper Ponce formation. (Corresponds with the Quebradillas limestone.) 78. Three kilometers west of Ponce. Upper Ponce formation. 95. Near K. 28 Lares road. San Sebastian shale. 96. A short distance west of Lares on the Lares road. San Sebastian shale. 98. In the railroad cut near the bridge over the Guajataca River, nortb coast, Quebradillas limestone. 176. Vicinity of Moca. Lares formation, shale facies HUBBARD, TERTIARY MOLLUSGA FROM LARES DISTRICT 85 SYSTEMATIC DESCRIPTIOIsr OF SPECIES Genus Atrina Gray Atrina rabelli, new species Plate X, Figure 1 Margins of sliell are arcuate strongly folded upward, particularly the anterior and posterior portions; central convex zone with flat lateral slopes, the cross-section of the valve being broadly V-shaped; surface marked by small, regular concentric ripples which become obsolete on the lateral mar- gins; central convex zone marked by two low radial ribs which die out near the ventral margin. Length 71 mm., semi-diameter 15 mm., height 100 mm. A single external mold was found showing only the ventral half of the shell. It is a large, rapidly widening form of the type of A, chipolana Dall, but is distinct from any form yet described. This shell is named in honor of Senor Rabell, geologist, of San Sebastian, who has taken an active interest in the geological work of the N. Y. Academy of Sciences and rendered every possible assistance to the geologists in their field work. Locality.—204. Horizon.—Quebradillas limestone. Genus Pecten Miiller Pecten (Pecten) laresense, new species Plate X, Figures 2, 3 Shell small of the concavo-convex type; right valve extremely convex, left valve shallow concave; shell equilateral; ears small and strongly ribbed radially; right valve with twenty-seven square smooth ribs and nearly flat interspaces of equal width, marked by fine, sharp, raised concentric threads which rise on the sides of the ribs; left valve with similar ribs and inter- spaces but with ribs medially grooved distally; ears of left valve with imbri- cate radial threads; anterior ear of left valve concave and correspondingly convex in the right; byssal notch small, ctenolium apparently lacking; sub- margins on both valves absent, the ribs extending to the base of ear; interior grooved and Urate ventrally; cardinal crura obscure and irregular; small amorphous pair of auricular crura; provinculum distinct; adductor scars markedly posterior. A right valve measures in length 20 mm., height 17 mm., diameter 8.5 mm.; left valve measures in length 20 mm,, height 17 mm., 'oncave diameter 2 mm. This shell is distinct from any other Pecten in the Porto Rican ^'aima. 86 SCIENTIFIC SURVEY OF PORTO RICO Type localities,—231, 232, 233. Other localities,—2^2 (b), 126, 118, 236, 1. Horizon.—San Sebastian shale. (abundant and widely dis- tributed.) Pecten (Euvola) reliquus Brown and Pilsbry variety portoricoensis, new variety Plate X, Figure 4 Only right valves were found, which agree closely with the speci- mens of P. reliquus in the Cohimbia University Gatini collections. The Porto Rican shell differs in having fewer, higher ribs with narrow interspaces, and in having the lateral slopes faintly ribbed instead of smooth as in the Gatun shell. The most perfect right \'alve has fourteen strong roimded ribs with several faint ones on each lateral slope. Length 35 mm., height 34 mm., diameter 3 mm. Fragments were collected showing a size of at least 50 mm. The left valves seem to have been easily destroyed, as none were found in the Panama collections. Type locality,—165. Other localities.—161, 198. Range.—Cibao limestone to Qnebradillas limestone. Pecten (Nodipecten) nodosus Linne Plate X, Figure 5 Pecten nodosus Linne, Syst. Nat., No. 164, 1758. Pecten. magniflcus Gabb, Trans. Amer. Phil. Soc, XV, p. 256, 1873 (not of Sowerby). Pecten {Nodipecten) 7iodosus Dall, Trans. Wagner Inst. Sci., Ill, pt. 4, p. 717, 1898. Pecten (Nodipecten) nodosus Maury, BuU. Ainer. Paleont., V, No. 29, p. 180. 1917. The specimens show three prominent strongly nodose ribs, one ii^ center of valve and two lateral. These alternate with two low(^r, sub nodose ribs marked by a median and two lateral threads. Th< subnodose ribs break up into scaly threads adjacent to the snh margins. The most perfect specimen measures in lengtli 20 mm • HUBBARD, TERTIARY M0LLU8CA FROM LARES DISTRICT HI keiglit 28 miii., semi-diaineter 7 mm., but fragments were found showing a height of 40 mm. Type locality,—198. Other locality.—42. Horizon,—Qiiebradillas limestone (not abundant). Pecten (Chlamys) collazoensis, new species Plate XI, Figure 1 Shell small, slightly convex; surface with twenty-one to twenty-two rounded ribs and narrower rounded interspaces; ribs ornamented Avith fine, thin, erect scales extending the whole width of the rib, and on either side at juncture with the interspace, a row of minute, densely crowded, bead-like spinules, which are much smaller and more densely crowded than the scales on tops of the ribs. Submargins and ears sculptured with a continuous series of squamose radial threads; anterior ear (of right valve) longer than the posterior ear, and with deep byssal notch. Length 11.5 mm., height 12.5 mm., semi-diameter 2 mm. No well preserved left valves were found. This shell is apparently the progenitor of P. portoricoensis. Localities,—CoWsizo Falls, 232, 233 ? llorlzon.—Lower ? San Sebastian shale, (some doubtful specimens were found in the upper part of the San Sebastian shale.) Pecten (Ohlamys) portoricoensis, new species # Plate XI, Figures 2, 3 The typical form is a moderate sized shell (length 24.5 mm., height 26.5 mm., diameter 9 mm), equivalve, sub-equilateral; ears moderately large, un- equal (anterior larger); byssal notch large but not deep; ctenolium incon- spicuous; single pair of cardinal crura; valves grooved within, and scalloped and Urate at ventral margin; surface with twenty-six to twenty-seven rounded libs and slightly narrower, flatly rounded interspaces; ribs ornamented with one to three rows of fine spinose scales which in the young shells show a tendency toward the beaded ornamentation of P. collazoensis. This feature usually persists longer next the submargins than centrally. Following this J*- collazoensis stage, the ribs and interspaces become smoother, the latter i'^latively broader; a medium thread or keel appears on each rib, and on bis keel the small scales become narrower, more spinose and more widely paced. When the shall is half grown, lateral keels, similarly spinose, appear )w down on the sides of the ribs. These correspond in position with the literal beads of the P. collazoensis stage but there is always a gap between 88 SCIENTIFIC SURVEY OF PORTO RICO the two where the sides of the ribs are smooth. Finally, in the adult, an interstitial thread, ornamented like the keels, appears in each interspace. In the last stage of some adult specimens an additional pair of spinose lateral keels appears one on each side of the median keel. On the lateral slopes next the submargins the ribs break up into densely squamose threads, which, decreasing in size, continue in unbroken series across the submargins and the ears. The right anterior ear differs from the others in having a strongly rugose area adjacent to the submargin, and above this the radial threads are strong and coarsely squamose. Camptonectes striation is very plain on un- worn specimens. This is an extremely variable shell, apparently related to P. the- tides Sowerby. It is the most abundant Feden in the Tertiary of north side of the island and numerous specimens show intergrada- tions between the different varieties, thus fortunately preventing the error of making two or more species. The typical forms are es- pecially interesting in that they show the species to have been de- rived from P. (Chlamys) collazoensis, which was not found in hori- zons above the San Sebastian shale. P. portoricoensis ranges from the San Sebastian shale through the Lares limestone, and has been found by Dr. Berkey in the Ponce limestone on the south side of the island. This shell is obviously derived from P. coUazoensis, and both might conceivably be included under one specific name. The latter, how- ever, retains its typical ornamentation throughout, without the slightest tendency toward a change, whereas in P. portoricoensis the P. collazoensis stage has become so accelerated that it is unnoticeable in some specimens and absolutely lacking in variety reticulatis. Type localities,—2U, 235, 343. Other localities.—2Z2, 118, 261, 1, 332, 76, and Collazo Falls, 244. Stratigraphic range.—Throughout the San Sebastian shale, and in the lower Lares limestone also found by Dr. Berkey in the Juana Diaz shale. Pecten (Chlamys) portoricoensis, new species variety reticulatis Plate XI, Figure 4 Shell, while smaller than the type, is similar in every respect, except that in the young the ribs are crossed by fine, sharp, densely but evenly spaced HUBBARD, TERTIARY MOLLUSGA FROM LARES DISTRICT 89 concentric lamellae, which thicken slightly on crossing the ribs, the whole producing a reticulate ornamentation. This feature is most noticeable cen- trally, since adjacent to the submargins are the typical scales, which do not appear until later on the ribs of the central portion of the shell. The reticu- late ornamentation persists until the shell has reached one-quarter or one- third adult size, and is then replaced by the typical spinose scale. The lateral spinose keels and the interstitial threads do not appear until the shell has reached maturity. Average size specimen measure in length 16.5 mm., height 18 mm., diameter 6 mm. The largest specimen measures 24 mm. in height. Type localities,—34:S, 619. Other locality.—74. Range —San Sebastian shale and Lares formation. Pecten (Chlamys) portoricoensis, new species variety grandis Plate XI, Figures 5, 6 This shell differs from the type and from variety reticulatis chiefly in its much greater size, and, except in gerontic individuals, in its relatively flatter valve. Unfortunately the specimens are all more or less worn in the umbonal region, but the reticulatis orna- mentation seems to predominate in the young. Some specimens, however, show in the young shell in P. collazoensis ornamentation, especially near the submargins. In some individuals the interstitial thread does not appear until the last stages of growth. In others it appears early but is not spinose until the adult stage is reached. In still others the ribs remain unornamented until the adult stage, though this may be due partly to wear. In the largest shells there are five threads on the ribs in the last stages of growth, and two additional threads sometimes appear in the interspaces. The camp- tonectes striation is obscured by the growth lines, which are es- pecially strong in this variety. A large flat-valved specimen measures in length 36 mm., height 39 mm., semi-diameter 8.5 mm. In this specimen the ribs are low and broad. A gerontic shell from the San Sebastian shale measures, in length 30 mm., height 32 mm., semi-diameter 8.5 mm. These geron- tic shells show a perodic swelling and contraction of the ribs and are 90 SCIENTIFIC SURVEY OF PORTO RICO notably convex. Superficially^ they look like another species, es- pecially Avhen the ribs are worn smooth. Type localities,—76, and K. 29.2 Lares road. Other localities,—168, 229, 263, 72, 344, 233, 263 (bottom 3rd falls), 757, 165 ?, GoUazo Falls, and vicinity of Collazo (float), 140, 1, 261, 244. llange.—San Sebastian shale. Lares limestone, Cibao limestone. Pecten (Chlamys) grabaui, new species Plate XTT, Figure 1 Shell transversely sub-ovate, equivalve, moderately convex with the greatest convexity toward the umbones; length 27 mm., height 26.5 mm., diameter 11.5 mm.; iimbonal third of shell smooth, remainder with twenty- three low rounded ribs and slightly narrower shallow rounded interspaces; following the smooth stage appear faint regular widely spaced raised con- centric threads, strongest on the ribs, which become more distinct as the ribs increase ventrally. These threads then become irregular, break up into three rows of fine sharp scales on the ribs. The ribs become threaded and grooved distally, the scales giving a squamose character to the threads. There are as many as five of these longitudinal threads on the distal portions of some ribs. Likewise, in the interspaces an interstitial thread appears which is similarly squamose. Thus in the final stage of growth there is a typical Chlamys ornamentation. On the lateral slopes the ribs break up into squamose radial threads, which continue across the submargins and ears: ears unequal, the anterior ears being longer and more strongly sculptured; byssal notch deep; ctenolium fine; double pair of cardinal crura; auricular crura low, indistinct; camptonectes striation strong. In first going over the specimens it seemed as though three or four species were represented, but intermediate forms made it neces- sary to group them as variations of an exceedingly variable specie>^. similar to P, {Chlamys) indecisus Dall, a form from the Vicksburii Oligocene. Like the latter, this shell shows variations which ar< intermediate between a true Chlamys and an Amusium, As thi type of the species, that form is chosen wliich best illustrates th' greatest number of characters common to the group. Type localities,—343, 619. Horizo7i,—Lares formation. HUBBARD, TERTIARY MOLLU^CA FROM LARES DISTRICT 91 Pecten (Chlamys) grabaui, new species variety aguadensis Plate XII, Figure 2 Shell moderately convex in umbonal region, nearly flat ventrally; surface nearly smooth, but with obsolete ribs visible chiefly as orange colored rays in the epidermis; camptonectes striation distinct; concentric lamellae, char- acteristic of the group, visible only under a lens. They are frequently worn off, leaving microscopic impressed lines in their place; submargins radially striate; ears rather strongly radially sculptured as in the other varieties; interior of shell strongly Urate, the lirae being paired and corresponding with the juncture of rib and interspace on the exterior. The interior is otherwise the same as in the other varieties; ctenolium distinct; length 18.5 mm., height 18.5 mm., semi-diameter 3.5 mm. This interesting variety is a typical Chlamys in slia])e but has many of the characters of Amusium. It seems to be the primitive member of this group, since the other varieties pass through the smooth aguadensis stage more or less early in growth and develop the ribbed stage. Localifdes.—619, 333, 331. Horizon .—Lares form ation. Pecten (Chlamys) grabaui, new species variety hatoensis Plate XII, Figure 3 Ribs appear very early, and become high and rounded; concentric lamellae regular and widely spaced, but becoming irregular near ventral margin where the ribs are radially grooved and interstitial thread appears in each interspace; submargins radially striate; ears strongly sculptured; ctenolium distinct; crura as in the type form; lirae obsolete except distally. Length 21.5 mm., height 21 mm., diameter 8.5 mm. Some specimens do not reach the high ribbed stage, but ribs are lather low and rounded throughout, with the concentric lamellae crowded ventrally and showing a tendency to alternate in strength. Another specimen from a higher horizon and which may be a muta- ion from this variety, has high, strong ribs, in which the irregularity "f the lamellae, grooving of ribs, and interstitial threads appear much ' 'irlier in the growth of the shell, and in the interspaces shows as 'i^my as thee interstitial threads in the final adult stage. 92 SCIENTIFIC SURVEY OF PORTO RICO Type localities,—332, 225. Other localities.~~34:3, 229, 333, 287, 167 ?, 62. Range.—Lares formation to Cibao limestone. Pecten (Chlamys) grabaui, new species variety guayabensis Plate XII, Figure 4 Shell marked by smooth submargins. The specimens can be arranged into a series, as in variety hatoensis, varying from low to high, strong, rounded ribs, and with concentric lamellae varying from simple and distinctly spaced, to irregular and crowded. As in variety Jiatoensis, the ribs appear early, covering the entire shell except the prodissoconch. Interior of the shell faintly Urate throughout. Shell otherwise like the type form of the group. The largest specimen measures in length 17 mm., height 17.5 mm., semi- diameter 4.5 mm. Type localities.—62, 332. Other locality.—282. Range.—Lares formation to Cibao limestone. The probable relationship of the group is shown in the following' table. Table 1 Pecten {Chlamys) grahaui, new species Horizon Cibao limestone Lares formation San Sebastian shale Group with smooth submargins variety guayabensis (shell ribbed) variety aguadensis - (shell smooth) Group with striate submargins variety hatoensis (shell ribbed) P. grahaui (type form) (partially ribbed) HUBBARD, TERTIARY MOLLUSCA FROM LARES DISTRICT 93 Pecten (Ohlamys) hodgii, new species Plate XII, Figure 5 Shell sub-ovate, sub-equilateral, strongly convex in umbonal region, slightly convex in ventral region; ears sub-equal, deep byssal notch and strong ctenolium; surface with twenty rounded ribs and deep, rounded, narrower interspaces; both ribs and interspaces grooved with fine radial threads which are densely spinose; ears and the rather broad submargins marked by sub- spinose radial threads; inner margin strongly scalloped and interior grooved. In the early stages of growth the ribs are not radically threaded, and the ornamentation consists of closely spaced, minute, sharp trans- verse scales on the ribs which join with raised concentric lamellae in the interspaces. When the shell has reached one third full size, the radial threads appear and the scales break up into minute densely spaced spines, which, ventrally, become elevated, curved, and TJ- shaped with concave side toward the beaks. Throughout most of the early stages the interspaces are devoid of threads and spinules, which appear much later than they do on the ribs. The concentric lamellae become obsolete ventrally. This shell is apparently closely related to an unlabelled specimen in the Kemp collection from Gatun, which seems to be a new species. In the latter the transverse scale stage is retained longer, the con- centric lamellae are noticeable throughout, and the spinules are not long or conspicuous as in the Porto Eican shell. If they are related, the Gatun shell would seem to be the more primitive of the two. It may be related to P. oxygonum canalis and P, oxygonum optimum of Brown and Pilsbry and to P. gahbi Dall. Dr. Maury has de- scribed a similar and apparently related shell P. camuycencis from the Quebradillas limestone. One complete right valve and some frag- ments Avere found. This shell is named in honor of Dr. Edwin T. Hodge, who studied the geology of the Coamo District, Porto Eico. Locality,—314. Horizon,—-Quebradillas limestone (rare). Pecten (Aequipecten) lobecki, new species Plate XIII, Pigure 1 Shell sub-orbicular, equilateral, moderately convex, ears large, smooth, pparently sub-equal (portion of anterior ear concealed) ; shell sculptured ith fourteen strong rounded ribs and sub-equal rounded interspaces; con- 94 SCIENTIFIC SURVEY OF PORTO RICO centric sculpture of fine raised lamellae, strong in the interspaces, obsolete ol tops of the ribs; fine concentric striae in the interspaces between the lamellae, and from one to three radial threads in each interspace, which with the con- centric lines produce a cancellate structure. The ribs are nearly smooth apparently because of wear, but occasionally show faint radial threads distally; submargins narrow, smooth, not depressed. Length 25 mm., height 24 mm., semi-diameter 4 mm. A Single left valve was found which resembled in some respects P. cercadica Maury. Locality.—619. Horizon,—Lares limestone. Pecten (Plagioctenium) rabelli, new species Plate XII, Figure 6 Shell suborbicular, slightly oblique in adult, sub-equivalve (right valve slightly more convex); ears small, subequal; shell with thirteen to fourteen strong, smooth, rounded ribs, with slightly narrower, smooth rounded inter- spaces; right anterior ear with faint radial theads, other ears smooth; sub- margins narrow, smooth, depressed, ctenolium distinct. The surface of the valves presents no very marked feature to the unaided eye, but under a strong lens, very minute, closely, evenly spaced and remarkably regular concentric lines are visible, crossing the entire shell, including the ears. In the largest specimens a gerontic character appears in the periodic swelling and con- tracting of the ribs. These gerontic shells are more convex than the others. Length 36 mm., height 34 mm., semi-diameter 8 mm. A smaller specimen has a semi-diameter of 5 mm. Localities.—K. 29.2-29.3 Lares road, K. 25 Ponce-Adjuntas road, Juana Diaz, Yauco. Horizon.—San Sebastian shale, Juana Diaz shale. Pecten (Plagiocteniimi) cercadica Maury Plate XIII, Figures 2, 3 Pecten cercadica Maury, Bull. Amer. Paleont., V, No. 29, p. 188, PI. 34, fig. H. 1917. Shell bilaterally symmetrical, sub-equivalve (right valve of slightly greater convexity); submargins broad, smooth except for faint growth lines; ears large, sub-equal, nearly smooth, triangular in outline except the right anterior, which is marked by deep byssal notch and byssal sulcus below, an<i surface of ear with five imbricated radial threads; ctenolium absent o obscure; other ears marked by very faint radial threads or striation, stronges HUBBARD, TERTIARY M0LLU8GA FROM LARES DISTRICT 95 near base of ear; surfaces of valves similar and marked by fourteen to seven- teen strong rounded ribs and slightly narrower interspaces, the whole crossed by fine close growth lines, periodically incised so as to give the effect of obscure beading of the ribs, a feature not evident on worn specimens; valves grooved within, but Urate only near ventral margins; single pair of strong cardinal crura. Average size;—length 21 mm., height 21 mm., semi-diameter 3.5 mm.; largest specimen;—length 26 mm., height 27 mm., semi-diameter 4.5 mm. This shell resembles P, (^Plagioctenmm) andersoni Arnold of the Pacific Coast Miocene, but is smaller. The latter species differs in having the left valve more convex than the right. The shell here described appears to correspond to Maury's description which was based on a left valve only. Type localities,—61d, 333, 324. Other localities.—331, 227 (top 30 feet). Horizon.—Lares limestone. Pecten (Plagioctenium) borinquenense, new species Plate XIV, Figures 1, 2 Shell sub-orbicular, sub-equivalve, slightly oblique, sub-marginal slopes slightly concave (left valve slightly less); sculpture of the two valves dis- similar. Right valve with sixteen to nineteen strong flat ribs of T-rail cross- section, wider than interspaces, especially in the unworn specimens where the lateral overhang obscures the borders of the interspaces; interspaces rounded and sculptured with raised concentric threads, very regular and evenly spaced (one-fifth mm. apart in ventral part of shell) ; tops of ribs marked by obscure median keel; concentric threads cross the ribs and are bowed up in the form of lamellae on crossing the median keel. The ribs are usually worn smooth showing the lamellae on top as a series of V-shaped striations; ears sub-equal, small; hinge line less than half the length of shell, sub-margins nearly smooth; ctenollum obscure and marked by deep byssal groove bordering the line of teeth; byssal notch small; adductor scar large, central; left valve with seventeen to twenty-one strong, high, rounded ribs and sub-equal rounded interspaces; both ribs and interspaces crossed by fine raised concentric threads, somewhat irregular and more distantly spaced than in the right valve, and worn or obscure on crossing the ribs; ars sub-equal and sculptured by radial grooves and incremental lines; sub- inargins as in the right valve. Interior of both valves smooth or faintly ^uted, but strongly fluted and lirate around the ventral margins; greatest onvexity in the umbonal region. The ribs of both valves are rounded in the «pionic stage. Adult shell measures in length 32 mm., height 31 mm., ^ameter of right valve 10 mm. 9G SCIENTIFIC SURVEY OF PORTO RICO This shell has ribs similar to P. diegensis Dall of the Pacific Coast Pleistocene, but is otherwise a different shell. Maury's P. caimitica, sl single left valve from the Santo Domingo Miocene is similar to the left valve of this shell. Locality.—313. Horizon.—Upper Quebradillas limestone. Genus Amusium Bolten Amusium papjnraceum Gabb Pleuronectia papyracea Gabb, Trans. Amer. Phil. Soc, V, p. 257, 1873. Amusium papyraceum DaU, Trans. Wagner Inst. Sci., Ill, pt. 4, p. 718, 1898; Idem, pt. 6, p. 1586, 1903. Amusium papyraceum Maury, BuH. Amer. Paleont., V, No. 29, p. 190, PI. 26, fig. 22, 1917. Found only in fragments, indicating a size of 35 by 36 nun. Localities.—118, (talus), 261. Horizon.—San Sebastian shale. Amusium mauryi, new species Plate XIV, Figure 3 Shen smaU, thick, moderately convex, entirely smooth except for very fine growth lines; ears sub-equal, large, sub-triangular; juncture of ears with shell slightly depressed, but not otherwise marked off. The interior of the valve is inaccessible, but there seem to be no internal ribs or else very obscure ones. They do not show on the exterior, and there are no radial rays or striations of any sort. The shell is unusually solid. It is' probably related to A. luna Brown and Pilsbry, and to A. mortoni Ravenel, but differs from these in its small size and relatively much larger ears. Length 19 mm., height 19.5 mm., semi-diameter 3 mm. A single left valve, which Avas at first included with the specinlen^ of A. papyraceum. Dr. Maury, in looking over the specimens, pointed out the mistake. Locality.—CoUazo Falls. Horizon.—San Sebastian shale. Amusium (Propeamusium) hollicki Maury Locality.—75. Horizon.—San Sebastian shale. HUBBARD, TERTIARY M0LLU8CA FROM LARES DISTRICT 97 Genus Spondylus Liiine Spondylus bostrychites? Guppy Spondylus hifrons Sowerby, Quart. Jour. Geol. Soc, VI, p. 53, 1849; not of Goldfuss, Petref., II, p. 99, pi. 106, figs. lOa-c, 1835. Spondylus hostrychites Guppy, Proc. Sci. Assoc. Trinidad, p. 176, 1867. Spondylus hostrychites Gabb, Trans. Amer. Phil. Soc., XV, p. 257, 1873. Spondylus 'bostrychites Dall, Trans. Wagner Inst. Sci., Ill, pt. 4, p. 758, 1898; pt. 6, p. 1586, 1903. Spondylus ItostrychUes Maury, Bull. Amer. Paleont., V, No. 29, p. 190, pi. 32, fig. 4, 1917. A small internal mold of a Spondylus^ which, because of its small hinge area and sub-equal valves, is identified doubtfully with the above species. Length 22 mm., height 26 mm., diameter 15 mm. Localities.—162, 23?, 126. Range.—San Sebastian shale to Cibao limestone. Spondylus gumanomocon Brown and Pilsbry Spondylus americanus Gabb, Trans. Amer. Phil. Soc, V, p. 257, 1873; not of Lamarck. Spondylus gumanomocon Brown & Pilsbry, Proc. Acad. Nat. Sci. Phila., p. 514, 1912 (footnote). Spondylus gumanomocon. Maury, Bull. Amer. Paleont., V, No. 29, p. 191, 1917. An internal mold and a fragment of the external mold were found of a shell which is like 8. gumanomocon but somewhat smaller. It may be a small variety or the young shell. Lower valve strongly convex, beak long, erect; surface with strong ribs 5 mm. apart, ap- parently spinose, and alternating Avith three or four small obscure ribs. The ribs are slightly wavy; upper valve orbicular, slightly convex; ribs known only from the internal mold but seem to be like those of the upper valve except that they are finer ; hinge line about 24 mm. in length. The internal mold shows the beak of the lower valve to be considerably excavated. Length 55 mm., height of lower valve 66 mm., of upper valve 54 mm., diameter 29 mm. From the proportions of the internal mold it Avill be seen that this shell is less elongate than S. gumanomocon as described from Santo 1 )omingo. The upper valve is much flatter than the Gatun species, *S'. scotti Brown & Pilsbry^ but the shell is about the same size as the latter and is similarly sculptured. Localities.—140, 162. Range,—San Sebastian shale to Cibao limestone. 98 SCIENTIFIC SURVEY OF PORTO RICO Genus Ostrea (L) Lamarck Ostrea antiguensis Brown Plate XV, Figure 1 Ostrea antiguensis Brown, Proc. Acad. Nat. Sci. Phil., p. 614, PI. 19, fig. 7; PI. 20, figs. 1, 5, 6, 1913. These shells were at first regarded as a variety of 0. hmtensis, but on comparison, were found to be the same as Dr. Maury's Porto Rican specimens, identified by Dr. Pilsbry as 0. antiguensis, ac- cordingly that determination is accepted, although it is difficult to believe that the reflexed character of the upper valve is a specific character. All of the specimens here described were taken from a zone of yellow chalk in the upper Quebradillas exposed in sea cliffs near Pt. Borinquen. The abundance of these large oysters is remarkable. They reach an enormous size and thickness, but the largest specimen collected measures in length 140 mm., height 130 mm., diameter (the two valves together) 110 mm. These forms are obviously geron- itc individuals. The lower valves are strongly curved upward ventrally toward the center, but are reflexed (or curved down) on the lateral margins. Likewise, the upper valves are curved down on the lateral margins, and strongly reflexed at the ventral margin, which results in a strong interlocking of the two valves. The upper valves are almost as thick as the lower ones. The upper valves reach their maximum thickness between the center and the ventral margin, and in both valves the animal has excavated its body cavity directly below the beaks by resorption of the prismatic layers at this point with increased deposition farther on toward the ventral mar- gin. Thus as seen in a longitudinal section of the shell these layers resemble the stratification in a migrating sand dune. The excavated bqdy cavity occupies but a small portion of the interior of the shell. Other specimens were found which, although almost as large as those above described, are apparently jiot gerontic individuals. The reflexed character of the upper valve is slightly or altogether absent, and the shell does not attain a great thickness. The spinose rib^ (about 9 irf number) and rounded furrows are well shown on these specimens, whereas they are obsolete or extremely irregular on th( gerontic forms. The adductor scar is high and nearly central in tb^ HUBBARD, TERTIARY M0LLU8CA FROM LARES DISTRICT 99 thin shells, but well toward the anterior margin in the gerontic shells. It is deeply impressed in the latter. The resilifer is re- markably small for shells of this size. Localities,—314; San Juan District (Semmes). Horizon.—Upper Quebradillas limestone. Also reported from the ^^Guanica shaly limestone" by Dr. Maury. Ostrea haitensis Sowerby 0. haitensis Sowerby, Quart. Jour. Geol. Soc. London, VI, p. 53, 1850. 0. haytensis Gabb, Trans. Amer. Phil. Soc, XV, p. 257, 1873. 0. veatchii Gabb, Pal. Cal., II. p. 34, PI. 11, fig. 59; PI. 17, fig. 21, 1869. 0. hermanni Conrad, Proc. Acad. Nat. Sci. Phila., V, p. 267, 1853. 0. vespertina Conrad, Pac. R. R. Rept, V, p. 325, PI. 5, figs. 36-38, 1855; Gabb, Pal. Cal., II, p. 107, 1869. 0. virginica Guppy, Quart. Jour. Geol. Soc, XXII, p. 577, 1866. Not of Gmelln. 0. virginica var. californica Marcou, Geol. No. Am., 1858. 0. haitensis Guppy, Quart. Jour. Geol. Soc. London, XXXII, p. 532, 1876. 0. haitensis Dall, Trans. Wagner Inst. Scl., Ill, pt. 4, p. 685, 1898. Idem, pt. 6, p. 1586, 1903. 0. haitensis Maury, Bull. Amer. Paleont., V, No. 29, p. 182, PI. 31, figs. 1, 2, 1917, The shells are rather thin, orbicular in outline, and strongly pli- cate with seven or eight sharply angular ribs, very high centrally at the ventral margin, and sharply angular furrows between. The ribs are not noticeably spinose; resilifer shelf-like, due to excavated beak; adductor situated in central-posterior portion of vale. The shells do not attain a large size, the largest specimen measuring in length 72 mm., height 74 mm., diameter of lower valve about 30 mm. Localities,—225, 800. Range.—Lares limestone, Cibao limestone. Ostrea haitensis Sowerby, variety! Plate XV, Figures 2, 3 Some small shells were found in which the lower valves are culptured like 0. haitensis, with spinose ribs, frequently angular, hile the upper valves are nearly smooth. The lateral inner mar- 100 SCIENTIFIC SURVEY OF PQRTO RICO gins adjacent to the beaks are finely creniilate, a feature not sho^^'ll in the specimens of 0. haitensis. Largest specimen measures in length 36 mm., height 43 mm., diameter lower valve 7 mm. A smaller more orbicular lower valve measures in length 22 mm., height 25 mm., diameter 6.5 mm. These little shells may be the young of 0. haitensis, or a variety. Locality.—62. Horizon,—Cibao limestone. Ostrea virginica Gmelin 0. virgiana of Lister and others. O.virginica Gmelin, Syst. Nat, p. 3336, 1792; Dilwyn, Descr. Cat, 1, p. 277, 1817; Lam., Anim. s. Vert, VI, p. 207, 1819. O.edulis Akerly, Am. Monthly Mag., II, p. 296, 1818 (not Linn§). 0. virginiana Sowerby, Genera, Ostrea, f. 2, 1822. 0. dorealis Lamarck, Anim. s. Vert., VI, p. 204, 1819. 0. canandenis Lamarck, op. cit., p. 207, 1819. 0. triangularis Holmes, Proc. Elliot Soc, I, p. 29, 1856. 0. fundata Holmes, Post-Pl. Foss. S. Car., p. 11, PI. 2, fig. 10, 1858. 0. semicylindrica Say, Jour. Acad. Nat Sci. Phila. (1), II, p. 258, 1822. 0. virginica Gabb, Trans. Amer. Phil. Soc, XV, p. 257, 1873. 0. virginica Guppy, Quart Jour. Geol. Soc. London, XXXII, p. 532, 1876. 0. virginica Dall, Trans. Wagner Inst. Sci., Ill, pt 4, p. 687, 1898. 0. virginica Maury, Bull. Amer. Paleont., V, No. 29, p. 184, 1917. The specimens show the nsnal great variation, but comparison with recent specimens of 0. virginica shows no constant differences. The Porto Rican shells vary from elongate, subtriangular to ovate: beak of lower valve nsually pointed, straight or slightly curved laterally; resilifer elongate in the large shells; lower valves are frequently of extreme convexity, Avhile the upper valves are gently convex or flat, but very irregular; beak of lower valve excavated. An average seized low^er valve measures in length 50 mm., height 90 mm., diameter 33 mm. Some are much broader, and a few specimens reach a much greater size and greater thickness. Color usually bluish, mottled with white. Type locality.—2S2, Other localities.—2S1, 65, 227 (top 30 ft), 7 to 8 (on road-flat Horizon.—Upper lares limestone (very characteristic). HUBBARD, TERTIARY MOLLUSGA FROM LARES DISTRICT 101 Ostrea sellseformis Conrad variety portoricoensis, neAv variety Plate XIII, Figures 4, 5, 6 Shell of moderate size, pear-shaped to elongate oval, never attaining very great thickness; valves dissimilar; lower valve with numerous radial ribs imbricated by raised laminae; resilifer deep; margins of ligament area marked by narrow groove which continues for some distance along the inner margins adjacent to the beak, and is denticulate (or marked by row of small pits) throughout; remainder of inner margin fluted by the ribs, or, in some specimens, smooth; adductor scar large, oval, nearly central; beak more or less curved laterally; upper valve smaller, convex to nearly flat; surface nearly smooth or marked usually by even, widely spaced, slightly raised concentric lamellae; beak curved laterally but less pointed than in lower valve, and with shorter ligament area; resilifer moderately impressed or even raised and convex in some individuals; lateral grooves indistinct or absent; inner margin crenulate adajacent to beaks, but smooth ventrally; adductor scar smaller than in lower valve and uniformly pear-shaped in all specimens. An average sized shell measures, lower valve, in length 62 mm., height 70 mm., upper valve, in length 42 mm., height 60 mm. Diameter (both valves) 19 mm. The upper valves of the young shells are more c(mvex. A typical young upper valve measures in length 23 mm., height 33 mm., diameter 7 mm. Type localities.—MZ, 333, 176, 59, 800. Other localities.—619, 332, 64. Range.—Lares limestone, Cibao limestone, Los Piiertos limestone. Ostrea collazica Maury Shell sub-elongate to sub-orbicular, heavy, attaining great thickness in large individuals; valves dissimilar; lower valve convex, with numerous small irregular radial plications which divaricate from a median or slightly posterior zone; plications flnely imbricated by thin, slightly raised laminae; beak strongly recurved laterally; ligamental area extremely long in large specimens; resilium deep but becoming shallow in gerontic individuals; margins of ligamental area marked off by narrow crenulated groove; inner margins near the beak finely crenulated; upper valve flat, with beak similarly recurved, usually more closely gyrate; surface smooth except for the thin laminae; interior similar to lower valve except for an amorphous, tooth-like process, located on the inner margin just anterior to the ligamental area, which is transversely denticulate or marked by cross grooves. In some speci- ^iiens the margins of both valves are similarly marked near the beaks; 'Ulductor scars of both valves large and situated slightly posterior. Average ize adult;—length 75 mm., height 85 mm. 102 SCIENTIFIC SURVEY OF PORTO RICO Fragments indicate that the shell reaches a considerably larger size, in which the lower valve is greatly thickened. Two of these large lower valves were found in which the tendency of the beak to curve laterally has apparently been almost lost, the beak being long and pointed. An unusual feature of this shell is the small amount of prismatic structure. Some of the specimens are made up almost entirely of nacreous laminae of micaceous thinness. This shell is of the 0, sellceformis divaricata type, and the young individuals might readily be taken for a variety of 0. sellwformis. The full grown flat upper valves with their closely gyrate beak bear a strong resemblance to 0. vaughni Dall of the Tampa Silex beds. Type localities.—7 to 8 (float), Lares road just east of Collazo bridge, K 29.2 to 29.3 Lares road. Other localities.~-100, 226, 231, 233, 267, 89, 232(b), 236. Range,—San Sebastian shale to Lares limestone. Characteristic of the San Sebastian shale, and occuring in the lowest fossiliferous zone of the latter. Ostrea cahobasensis Pilsbry and Brown variety portoricana, new variety Plate XVI, Figure 1 ; Plate XVII, Figure 1 SheUs reach a very large size, and are characterized by their elongate form and long, pointed, and usually straight beak. The young shells are much less elongate in form. The body cavity tends to remain the same size during growth, most of the addition in height being in the beaks. The resilifer is shallow in the lower valve, and convex in the upper valve, and in both valves it is bordered by a broad, prominent ridge on each side. The latter are marked off from the lamellae of the lateral slopes by a deep impressed zone, in which there is no trace of dentition or crenulation. The beaks may be twisted or straight, and there is considerable variation in the outline of the shells due to the accidents of growth. The shells apparently grew in crowded colonies. The lower valve is convex, the upper slightly convex, or nearly flat in the younger shells. The beak of the lower valve always pro- jects far beyond the beak of the upper valve, and in the young, is deeply excavated within, below the resilifer. The position of the adductor scar is variable, being rather high in the young, but travels ventrally with the growth of the shell, until, in the largest individuals, it is located at the ventral one-third or one-fourth of the shell. The large shells have an hour glass-shaped body cavity, consisting of a deep round cavity immediately below the resilifer, a contraction centrally, and a large crescent-shaped ventral cavity which begins opposite the adductor scar, and swings around below th^ HUBBARD, TERTIARY M0LLU8CA FROM LARES DISTRICT 103 scar, and close to the ventral margin. This is a fairly constant fea- ture of the larger shells, and is strongly developed in some of the young or half grown shells. The surface of both valves is marked only by concentric lamellae, and shows no signs of radial fluting of ribs. The lamellae are, however, occasionally quite irregular. This shell, while apparently answering the description of the Haitian species, shows differences of varietal rank. The largest specimen measures in length 100 mm., height 270 mm., diameter (both valves together) 95 mm. Localities.—^West of Guanica Mill in basal limestone a few feet above the contact with the Older Series (Lobeck) Fragments of a similar shell were found in the Lares limestone, but their identity with the Guanica shell is by no means certain. Horizons.—Ponce limestone, Lares limestone (doubtful). Genus Lithophaga Bolten Lithophaga nigra d'Orbigny Lithodomus niger d'Orbigny, De la Sagra, Hist. Polit. y Nat. Isla de Cuba, pt. 2, V, p. 351, 1845; Atlas, VIII, PI. 28, figs. 10, 11, 1855 (Spanish Ed.). Modiola carihwa Philippi, Abbild. u. Beschr., Ill, p. 20, PI. 2, fig. 5, 1847. Modiola antillarum Philippi, op. cit. p. 20, PI. 2, fig. 4, 1847; Zeitscher., p. 116 (not of d'Orbigny) ; young shell. Mytilus lithophagus Gibbes, S. Car. Cat., p. 22, 1848; not of Linne. Lithophagus nigra Morch, Cat. Yoldi, II, p. 56, 1853. Lithophagus antillarum Reeve, Conch. Icon., X, PI. 2, fig. 7, 1857. Lithophaga nigra Dall, Trans. Wagner Inst. Sci., Ill, pt. 4, p. 799, 1898; Bull. 90, U. S. Nat. Mus., p. 129, 1915. Lithophaga nigra Maury, Bull. Amer. Paleont., V., No. 29, p. 194, 1917. This shell is known from the Tampa Silex beds, and continues to the recent fauna of the Antilles. The recent shell of Cuba as described by d'Orbigny, has a length of 50 mm. The Porto Kican fossils differ only in size, the largest measuring in length 30 mm., l^eight 9 mm., diameter 8 mm. The occurrence is chiefly in the form of internal molds, but fragments of the shell show the vertical triae which end abruptly at a transverse oblique line extending rom the beaks to the posterior ventral margin. Locality.—225. Horizon.—Upper Lares limestone. 104 SCIENTIFIC SURVEY OF PORTO RICO Genus Leda Schumacher Leda peltella Dall Plate XVII, Figure 6 Leda acuta Gabb, Trans. Amer. PhU. Soc, XV, p. 255, 1873. Not L. acuta Conrad, 1832, nor Sowerby, 1887. Leda peltella Dall, Trans. Wagner Inst. Sci., Ill, pt. 4, p. 579, PI. 32, fig. 5; Idem, pt. 6, p. 1586, 1903. Leda peltella Maury, Bull. Amer. Paleont, V, No. 29, p. 161, PI. 26, fig. 9, 1917. One of the most abundant fossils in the Quebradillas limestone. The posterior sulcation is always broad and distinct ; anterior sulcatioii narrow and often indistinct. Length 11 mm., heigh 6.5 mm., semi- diameter 3 mm. 'No specimens were found less than 9 mm. in length, 'Type locality,—204. Other locality.—660. Horizon,—Quebradillas limestone. Genus Area Linne Area yaquensis Maury Area yaquensis Maury, Bull. Amer. Paleont., V, No. 29, p. 164, PI. 30, fig. 14, 1917. Several specimens were found of a very small Area which closely resembles Maury's A. vaquensis, a somewhat doubtful species from the Santo Domingan Oligocene. The Porto Rican shells show no distinctive characters, and are placed with A, yaquensis because tliey correspond more closely to this than to any other species. Tlic specimens are very numerous and all about the same size, hence it is unlikely that they are young individuals. Length 8 mm., heiglH 4.6 mm. Type locality.—204. Other locality.—225. Range.—Lares limestone to Quebradillas limestone. HUBBARD, TERTIARY MOLLUSCA FROM LARES DISTRICT 105 Area dariensis Brown and Pilsbry Plate XV, Figure 5 Area dariensis Brown and Pilsbry, Proc. Acad. Nat. Sci. Phila., p. 362, PI. 22, fig. 10, 1911. Umbo prominent, at anterior third of shell; surface with thirty-three flat ribs and sub-equal flat interspaces, the whole crossed by fine raised concentric lines, strongest on ribs and giving to the latter a nodular appearance; ribs broaden anteriorly and posteriorly, the ten posterior and the five or six anterior ribs medially grooved. Length 26 mm., height 16.5 mm., semi- diameter 5.5 mm. This Area is smaller than the Gatun species, and may be a variety of it. It also resembles the shell described by Tonla as Area cf. consohrina Moore. Localities,—Collazo Falls, 261 ?, 232(b). Horizon,—San Sebastian shale. Area (Scapharca) cf. donacia Dall Plate XV, Figures 6, 7 Area (Scapharca) donacia Dall, Trans. Wagner Inst. Sci., Ill, pt. 4, p. 649, PI. 33, fig. 13, 1898. The size and sculpture answers DalFs description of this species, especially the raised concentric threads in the interspaces of the left valve, a feature lacking on the right valve. It differs from the Bowden form in the number of ribs (27), and in having a shallow median depression, strongest in the left valve. Length 8.5 mm., height 6.5 mm. A smaller shell measures in length 6.75 mm., height 4.5 mm. Locality,—204. Horizon,—Quebradillas limestone. Area, species indet. Plate XVII, Eigures 2, 3 Shell small, very convex; beaks at anterior third; anterior and posterior sitls equally rounded; hinge area broad, especially anteriorly, with beaks ' 'flely separate; surface with twenty-five broad, quadrate, rather low ribs and jually wide, shallow rounded interspaces; central ribs medially grooved ^'stally; hinge margin three-fourths the length of shell and slightly raised 106 SCIENTIFIC SURVEY OF PORTO RICO above hinge area; hinge area transversely grooved or striate posteriorly; teeth fine, numerous; interior of valves unknown. Average size measures in length 19 mm., height 10.5 mm., diameter 12 mm. Lrargest specimen meas- ures in length 25 mm., height 13.6 mm., diameter 16 mm. Type locality.—230. Other localities,—2'63, 232(b). Horizon,—Upper San Sebastian shale. Area (Scapharca) coUazica Maury The material collected by the writer consists only of internal molds. An average sized specimen measures in length 16.5 mm., height 9.5 mm., diameter 7.5 mm. Localities,-—SZ3, 619, 64, 232(b). Range,—Upper San Sebastian shale to Cibao limestone. Very abundant. Subgenus Barbatia Gray Barbatia (Acar) reticulata Gmelin Area reticulata Gmelin, Syst. Nat., VI, p. 3311, 1792. Area reticulata Sheldon, Palaeontographica Americana, I, p. 20, PI. 4, figs. 8-12, 1916. Barbatia (Acar) reticulata Maury, Bull. Amer. Paleont., V, No. 29, p. 166, PI. 30, fig. 16, 1917. A single fragment was found, sufficiently complete to identify. Length indeterminate, height 6 mm. Locality,—204. Horizon,—Quebradillas limestone. Barbatia cf. banaczyi Gabb Plate XIV, Figure 4 Barbatia bonaczyi Gabb, Trans. Amer. Phil. Soc, XV, p. 254, 1873. Area umbonata Dall, Trans. Wagner Inst. Sci., Ill, pt. 4, p. 620, PL 38, figs. 4, 4a, 1898. Not of Lamarck. Barbatia cf. bonaezyi Maury, Bull. Amer. Paleont., V, No. 29, p. 165, PL 30. fig. 15, 1917. A single external mold of a right valve resembling B, bonaczy Gabb, but smaller. It is nearer the size of B, cf. honaczyi describeii HUBBARD, TERTIARY MOLLUSCA FROM LARES DISTRICT 107 by Maiiry^ but the sculpture is coarser. It is very probably a variety, but the specimen is too poor for complete description. The ribs are crowded centrally and sparser at the ends of the valve. Those on the posterior slope lose their bearded character and become scaly. Valve with shallow median sulcation. Length about 12 mm., height 6 mm. Locality,—204. Horizon.—Quebradillas limestone. Genus Glycimeris Da Costa Glycimeris portoricoensis, new species Plate XV, Figure 6 Shell sub-orbicular; beaks not prominent; surface with about thirty strong sub-angular to rounded ribs and sub-angular interspaces, the whole crossed by fine raised concentric threads, regular and evenly spaced. The ribs near the ventral margin broaden rapidly at the expense of the interspaces, and become round in cross-section. Interior of shell unknown. Largest specimen measures in length 19 mm., height 17 mm., semi-diameter 4 mm. This shell resembles G. acuticostata Sowerby, but has broader, more rounded ribs. Localities,—204, 182, 318. Range.—Upper Los Puertos limestone to Quebradillas limestone (typical of the latter). Glycimeris collazoensis, new species Plate XV, Figures 4, 5 Shell sub-orbicular, beaks not prominent; hinge area short; teeth numer- ous, in uninterrupted series; surface with thirty-four low angular ribs and angular interspaces; each rib with fine keel or thread on the apex, and with the appearance of a groove on either side of this median thread; inner margin scalloped ventrally; length 15 mm., height 16 mm., semi-diameter, 4 mm. This shell resembles G. gatunensis Toula, but the latter is smaller 'Hid more transversely elongate. It also resembles G. portoricoensis 'f the Quebradillas limestone, of which it may posssibly be the pro- ^iiiitor. G, portoricoensis differs chiefly in its larger size, more ''^>unded ribs, and strong concentric growth lines. Locality.—261. Horizon.—Lower San Sebastian shale. 108 SCIENTIFIC SURVEY OF PORTO RICO Genus Venericardia Lamarck Venericardia scabricostata? Guppy Cardita scabricostata Guppy, Quart. Jour. Geol. Soc. London, XXII, p. 293, PI. 18, fig. 10, 1866. Cardita scabricostata Gabb, Trans. Amer. Phil. So€., XV, p. 252, 1873. Cardita scabricostata Guppy, Quart. Jour. Geol. Soc. London, XXXII, p. 531, 1876. Venericardia scabricostata Dall,, Trans. Wagner, Inst. Sci., Ill, pt. 6, pp. 1428, 1586, 1903. Venericardia scabricostata Maury, Bull. Amer. Paleont., V., No. 29, p. 198, PI. 33, fig. 1, 1917. Shell with prominent beaks; 18 to 20 high nodose ribs and nar- rower, V-shaped interspaces which are crossed by strongly marked growth lines; liinnle broad, short, and distinct. Length abont 4.5 mm., height 4 mm., semi-diameter 1.5 mm. The specimens found are much smaller than F. scabricostata, and yet seem to be mature shells; they may be a variety. Locality.—225. Horizon,—Lares limestone. Venericardia cerrogordensis Maury, new variety Venericardia cerrogordensis Maury, Bull. Amer. Paleont., V, No. 29, p. 199, PL 33, fig. 3, 1917. A single fragment of anterior half of a left valve, which seems to be a variety of this species, somewhat larger than the Santo Domingo shell. About fourteen strong ribs with strongly beaded keel; inter spaces wider than ribs, shallow, with wavy growth lines and showing an obscure crenulated radial thread on either side at base of rib- Length about 27 mm., height about 23 mm., semi-diameter, etc., 5.5 mm. This may be a distinct species but the specimen is so incomplct' that it has been identified with the nearest form. The specimen wjt found in a piece of road metal at K. 26.5 Lares road and its horizon is unknown. The rock is a white limestone like the Qucbradill'^ and contains a mold of Cliione cf. ivoodivardi Guppy. HUBBARD, TERTIARY MOLLUSCA FROM LARES DISTRICT 109 Genns Chama (Linne) Bruguiere Chama involuta Guppy Chama involuta Guppy, Geol. Mag. London, decade 2, I, p. 436, PI. 17, figs. 5a-c, 1874; Quart. Jour. Geol. Soc. London, XXXII, p. 531, 1876. Chama involuta Dall, Trans. Wagner Inst. Sci., Ill, pt. 6, pp. 1398, 1586, 1903. Chama involuta Maury, Bull. Amer. Paleont, V, No. 29, p. 199, PI. 33, figs. 4, 5, 6, 1917. The Porto Rican specimens are unusually large, but apparently of this species. The largest specimen is fragmental, but shows a height of 52 mm. Judging from the specimens, it attaches by either valve. The beak is strongly prosogyrate, making over one complete turn. The lamellae are strongly fluted, almost spinose on one specimen. Localities,—204, 98(Berkey). Horizon,—Quebradillas limestone. Chama portoricana, new species Plate XVII, Figure 5 Beak closely prosogyrate; surface with extremely crowded, thin, high lamellae, which on the largest specimen rise 8 mm. above the shell surface. These lamellae are quite regular, being gently fluted over the body of the shell, but spinose at the margin in the adult; shell marked by rounded um- bonal ridge; inner margin finely crenulate; cardinal area pustulose; strong bifid and crenulate cardinal tooth in the right valve, with crenulate lateral; shell attaches by either valve, but the cardinal tooth remains in the right valve in either case; adductor scars large; pallial line distinctly impressed. Length 48 mm., height 35 mm., diameter of convex valve about 12 mm. A smaller attached valve measures length 22 mm., height 18 mm., diameter 9 mm. This shell differs from C. congregatoides Maury in its more regular and higher lamellae, and in its more elongate form. Locality,—204. Horizon,—Quebradillas limestone. Genus Lucina (Bruguiere) Lamarck Lucina coUazoensis, new species Plate XVIII, Figures 1, 2 Shell transversely ovate, convex, produced posteriorly, beaks being slightly torward of center and frequently so close together that they practically touch; 110 SCIENTIFIC SURVEY OF PORTO RICO hinge line long and straight, nearly nine-tenths the length of the shell. The largest specimen, somewhat distorted so as to increase the convexity, meas- ures in length 65 mm., height 40 mm., diameter 45 mm. A smaller shell, not distorted, measures in length 39 mm., height 31 mm., diameter 25 mm. This is a ponderous shell of the type of L. corpidenta Dall, but unusual for its elongate form and long straight hinge line. It oc- curs chiefly as internal molds of both valves intact, but the form is often distorted by pressure. Fragments of external mold show the surface to be nearly smooth, marked only by fine growth lines, peri- odically incised at irregular intervals. There is an undescribed shell in the Kemp collection from the lower Gatun beds Avhich is apparently this species, or very close to it. Localities.—74, 92, 86, Collazo (float). Horizon.—^Ssm Sebastian shale (abundant at Collazo Falls). Lucina cf. chrysostoma (Meuschen) Philippi Plate XVIII, Figure 3 Tellina crysostoma Meuschen, Mus. Gevers., p. 482, 1787 (typographical error). Lucina chrysostoma Philippi, Abb. und Beschr. neue Conchyl., II, p. 206, PI. 1, fig. 3, 1847. Venus edentula Chemnitz, Conch. Cab., VII, PI. xl, figs. 427-9, 1784; Gmelin, Syst. Nat., VI, p. 3286, 1792; not of Linn^, Syst. Nat., ed, 10, p. 689, 1758. Anodontia alba Link, Beschr. Rostock Samml., p. 56, 1807. Lucina edentula Reeve, Conch. Icon., Lucina, PI. ii, fig. 9, 1850; Heilprin, Trans. Wagner Inst, I, pp. 102-3, 1886. Loripes chrysostoma Arango, Fauna Mai. Cubana, p. 257, 1878. Lucina chrysostoma DaH, Trans. Wagner Inst., Ill, pt. 6, p. 1354, 1903. Loripes edentula Gabb, Trans. Amer. Phil. Soc, XV, p. 251, 1873. Lucina clirysostoma Maury, Bull. Amer. Paleont, V, No. 29, p. 202, PI. 35, fig. 2, 1917. Eesembles L, chrysostoma of the Caloosahatchie Pliocene, but tb( largest and most convex specimens resemble the recent L. glohosa Forskol. Only internal molds have been found, which show luniil*' impression, and posterior sulcation close to dorsal margin. Tlic specimens range in length 39 mm., height 36 mm., diameter 22 min. to length 135 mm., height 115 mm., diameter 95 mm. Localities.—20^, 174. 10, 78, 98, 176? (Berkey). Mona Islami, south side of Vieques Island, Guanica, and Ponce (Lobeck). HUBBARD, TERTIARY M0LLU8GA FROM LARES DISTRICT 111 Horizons,—^Los Puertos, Quebradillas limestones, and Ponce for- mation. These large shells are very abundant as internal molds in the Tertiary formations of the north and south coasts. Genus Phacoides Blainville Phacoides (Miltha) riocanensis Maury Phacoides (Miltha) riocanensis Maury, BuU. Amer. Paleont., V, No. 29, p. 205, PI. 35, jag. 7, 1917. The Porto Pican shells are the same size as those of the Santo Domingan Oligocene. There seem to be no important differences. The former shells have a slight differentiation in the concentric lamellae, two lamellae of secondary strength alternating with each primary one. A shallow median sulcus is a noticeable feature near the A'cntral margin, but does not extend to the beak. Length about 47 mm., height about 45 mm., semi-diameter 7.5 mm. Localities,—336, 204, 220, 225, 318, 317. llange.—Lares limestone, Cibao limestone, Los Puertos limestone, Quebradillas limestone. Tliis species is widespread but not abundant. Phacoides (Miltha), species indet. Plate XVIII, Figure 4 SheU of moderate size, convex, slightly inequalateral; hinge area narrow, short, beaks incurved and nearly in contact; anterior margin broadly rounded, posterior margin roundly truncate, basal margin nearly straight; posterior sulcus close to margin; concentric sculpture of fine, even, raised lamellae, about 1/3 mm. apart at ventral margin, and with fine growth lines in the spaces between. Height of shell about 24 mm., length about 34 mm., semi- <iiameter 7 mm. Only a single fragment was found which was too incomplete for tin accurate description, but differed from any other species. This >hell resembles P. {Miltha) cf. smithwoodwardi Maury, a species rem the same horizon, but is more elongate. than the latter, and has he posterior sulcus much closer to the margin. Locality,—204. Horizon,—Quebradillas limestone. 112 SCIENTIFIC SURVEY OF PORTO RICO Phacoides (Miltha), species indet. Plate XVIII, Figure 5 Shell small, orbicular, moderately convex. Sculpture of fine concentric lamellae like P. hillsboroense; deep radial sulcus crossing the posterior one-quarter of shell and extending to ventral margin. Fine concentric striae between the lamellae are visible under a lens. Length 12 mm., height 12.5 mm., semi-diameter 3.5 mm. Only one specimen was found, the external mold of a left valve. It may possibly be the young of a large species like P. riocanensis. Locality.—52(a). Horizon.—Quebradillas limestone. Phacaides (Pseudomiltha) laresensis, new species Plate XVIII, Figure 6 Shell sub-orbicular, nearly equilateral, moderately convex; surface with concentric lamellae of the type of P. hillsdoroense, but very regular instead of wavy as in the latter; concentric striae between the lamellae; lunule narrow, deeply impressed; escutcheon large, marked off by a narrow sulcus which broadens at the posterior margin; concentric sculpture flexed sharply upward over the escutcheon, where it becomes coarser; surface of shell marked by faint radial striae; cardinal area edentulate; interior of shell unknown. The shell is thin, and in most of the specimens i3 worn partially or wholly away, leaving only the internal mold. Length 36 mm., height 34 mm., diameter 18 mm. Localities.—262, Collazo Ealls, 232(b) ? Horizon.—San Sebastian shale. Phacoides (Lucinisca) caUiounensis Dall Plate X, Figure 6 Phacoides (Lucinisca) calhounerisis Dall, Trans. Wagner Inst. Sci., Ill, pt. ^, p. 1371, PI. 52, fig. 16, 1903. Phacoides calhounsis Maury, Bull. Amer. Paleont., V, No. 29, p. 204, 191". (Typographical error.) These shells are variable but have the same general characters si> the Florida form. The majority of the specimens are the same si/<' as the latter, but occasionally attain a considerably greater size. Tie greater prominence and spai^city of the concentric ridges in the inn- HUBBARD, TERTIARY MOLLUBGA FROM LARES DISTRICT 113 bonal region is a noticeable feature. The radial ribs are finer and somewhat crowded on the posterior slope and to a lesser extent on the anterior slope. Dall does not mention this character but it may be observed in his illustration. The intersections of the radials with the concentric ribs have a tendency to form spinose nodes, especially in the adult stage near the lateral margins. This gives the shell a superficial resemblance to P, hispaniolana Maury, but the sculpture of the latter is much finer. The Porto Eican shell has a large and distinct lunule. An average size specimen measures in length 10 mm., height 9.5 mm., semi-diameter 2.5 mm. The largest specimen measures in length 13 mm., height 12 mm., semi-diameter 4 mm. Type locality.-—204. Other localities.—52(a), 77(Berkey). Horizon.—Quebradillas limestone (abundant) ; Ponce limestone. Genus Divaricella Von Martens Divaricella prevaricata Guppy Divaricella vrevaricaiaQw'^^y, Proc. U. S. Nat. Mus., XIX, No. 1110, p. 327, PI. 30, fig. 4, 1896. Divaricella prevaricata DaU, Trans. Wagner Inst. Sci., Ill, pt. 6. pp. 1389, 1587, 1903. Divaricella prevaricataM2i\iYy, BuU. Amer. Paleont, V., No. 29, p. 207, PI. 35, fig. 10, 1917. The divaricate lines are finer than those of the Santo Domingo shell. The single specimen found measures in length 7 mm., heiglit 5.75 mm. Locality.—204. Tlorizon.—Quebradillas limestone. Genus Codakia Scopoli Codakia (Jagonia) magnoliana Dall variety borinquenense, new variety Plate XVII, Figure 4 A single right valve was collected. It is slightly smaller than tlie ^^ssell described from the North Carolina Miocene, and the concentric ^ '^Ipture is more pronounced. The radials are slightly wavy as in 114 SCIENTIFIC SURVEY OF PORTO RICO Codakia oi'hicidaris, and increase by intercalation. They vary in strength, parts of the shell being marked by ribs finer and more crowded than in adjacent portions of the surface. The shell is noticeably inequilateral. The lunule is long and narrow. Length 10 mm., height 8 mm., semi-diameter 4 mm. Localities.—204, 671. Horizon,—Quebradillas limestone. Genus Cardium (Linne) Lamarck Cardium (Laevicardium) cf. serratum Tiinne Cardium serratum Linn^, Syst. Nat., ed. 19, p. 680, 1758. Cardium Iwvigatum Lamarck, Anim. s. Vert., VI, pt. 1, p. 11, 1819 (not of Born, Mus. Vind. Test., p. 47, 1780; nor of Linn§, Syst. Nat., X, p. 680, 1758). Cardium citrinum Wood, Gen. Conch., p. 223, PI. 54, fig. 3, 1815. Liocardium pictumUsLvenel, Proc. Acad. Nat. Sci. Phila., for 1861, p. 44, 1862. Cardium hiatus *'Meuschen" fide Krebs, W. I. Cat. Shells, p. 115, 1864. Vardium lineatum Krebs, op. cit., not of Gmelin, 1792. Cardium pristis Valenciennes, fide Krebs, op. cit. Cardium oviputamen Reeve, Conch. Icon., Cardium, PL 7, fig. 36, 1844. Cardium venustum Gabb, Trans. Amer. Phil. Soc, XV, p. 251, 1873. Cardium serratum Dsill, Proc. U. S. Nat. Mus., XIX, No. 1110, p. 327, 1896; not serratum of Pennant, 1778). Cardium serratum BaXif (in part), Trans. Wagner Inst. Sci., Ill, pt. 5, p. 1110, 1900. Cardium serratum Brown and Pilsbry, Proc. Acad. Nat. Sci. Phila., p. 367, 1911. Cardium serratum Maury, Bull. Amer. Paleont., V, No. 29, p. 212, PI. 36, fig. 8, 1917. Numerous internal molds apparently of this species, and of about the same size as those of the Santo Domingo Oligocene were found. They average about 20 mm. in height. Fragments of external mold show numerous fine thread-like radial ribs. Some specimens show n slight radial sulcation anteriorly. Localities.~~~2Q4, 225, 333?, 64. Range,—Lares limestone to Quebradillas limestone. Cardium (Trachycardium) muricoides, new species Plate XIX, Figure 1 Shell sub-ovate, convex; surface with about 36 spinose ribs and narrowet, rounded, transversely striate interspaces; interior of valves grooved a^'^^ scalloped at ventral margins. All ribs except the three anterior ones have ;^ HUBBARD, TERTIARY MOLLUSGA FROM LARES DISTRICT 115 lateral keel on each edge at the top. The three anterior ribs have only one such keel, placed on the anterior side. The first ten ribs (including the three single keeled ones) are ornamnted with longitudinally ovate, long, erect, or slightly hooked spines along the anterior keel, but spreading out over the center of the rib. All the remaining ribs have the spines on the posterior side. From the eleventh rib to the eighteenth inclusive, the spines are like those of the ten anterior ribs, but commencing with the nineteenth rib the spines posteriorly become narrower, blade-like, set longitudinally on the rib, and curved posteriorly over the adjacent interspace. All the ribs are flat topped, but the posterior ribs have the tops sloping posteriorly. Length 30 mm., height 32.5 mm., semi-diameter 11 mm. This shell is twice as large as C, howdenense Dall. The orna- mentation especially of the rib is nearer to that of C. muricatum than to that of any other species. It is apparently related to C. (Trachycardium) gaiunensis Toiila, and is one of the early members of the (7. muricatum group. Type locality,—179. Other localities,—225, 24?, and (doubtfully) near Guanica Central (Lobeck). Range,—Lares limestone, Oibao limestone, Los Puertos limestone. Oardium (Trachycardium) cinderellse Maury variety alternatum, new variety Plate XIX, Figures 2, 3, 4 Shell equivalve, slightly inequilateral; beaks high, strongly incurved; hinge line rather long; surface with about thirty-six broad, flat ribs with narrow interspaces; ribs appear medially grooved when worn smooth. "When perfect, they show a single row of high, vaulted, inverted V-shaped spinose scales, which cover the width of the rib, and are somewhat unevenly spaced, though not crowded. There is a strong tendency toward alteration of ribs with large and ribs with small spines. This is more marked in some speci- mens than in others. It is a feature not mentioned in Maury's description of the Santo Domingo shell, but shows in the illustration of the latter. The interspaces are faintly grooved radially, and strongly transversely striate; valves internally grooved, and inner margins strongly scalloped ventrally. Length 29 mm., height 33 mm., diameter 26 mm. The sculpture is like (7. ciuderellce Maury, but the shell is larger, shorter, and more convex. It may possibly deserve a specific name, ^>ut the specimens are too fragmental to warrant this. Localities,—225, 226, 280, 281, 331. Horizon,—Lares formation. 116 SCIENTIFIC SURVEY OF PORTO RICO CarcUum (Trigonocardia) sambaicum Maury variety portaricoensis, new variety Plate XIX, Figures 6, 6 'No complete shells were found, but fragments large enough to show the outline of the shell. They seem to be quite variable. There are some specimens in which the ribs are worn smooth as in Maury's illustration from Santo Domingo. Some specimens show the ribs slightly wider than the interspaces, but usually the reverse is true, especially in the ventral portion of the shell. Tine raised concentric threads cross the interspaces and cross the ribs between the nodes. These threads are much finer and more crowded where they cross the ribs. In the interspaces they are very irregular, and frequently end short at the center of the interspace. These terminated threads have a tendency to alternate from opposite sides of the interspace as though shearing or faulting had displaced them. The nodes on the ribs are high and prominent. The shells are smaller and less convex than the Santo Domingo form, but the number of ribs, trun- cation and outline of the shell are about the same. Length 13 mm., height 13 mm., semi-diameter 5 mm. Locality,—204. Horizon.—Quebradillas limestone. Cardium, new species (aff. C. sambaicum Maury) Plate XIX, Figure 7 Fragment indicating a shell of the size and general outline of C. sambaicum Maury, but with a somewhat different sculpture of the ribs. Shell with about 25 strong ribs, high and rounded on top, an<l slightly narrower TJ-shaped interspaces. The whole is crossed by fine, close concentric threads, quite irregular, and of which every second, third or fourth one on crossing the ribs expand into broa<i semi-cone shaped scales the pieces of which are toward the beak These scales are irregularly spaced, and are especially crowded near HUBBARD, TERTIARY MOLLUSCA FROM LARES DISTRICT 117 the ventral margin. Where the ribs are worn, these scales appear as thin arched lamellae. Length of shell abont 20 mm. Locality.—204. Horizon.—Quebradillas limestone. Cardium (Trigonocardia) haitense Sowerby variety cercadicum Maury Plate XIX, Figure 8 Cardium haitense Sowerby, Quart. Jour. Geol. Soc. London, VI, p. 52, PI. 10, fig. 11, 1849 (in part). Cardium (Trigonocardia) haitense variety cercadicum Maury, Bull. Amer. Paleont., V., No. 29, p. 212, PI. 36, fig. 6, 1917. This shell corresponds closely to Maury's variety cercadicum of Santo Domingo. The truncation is sharp; ribs with inverted V- shaped nodules ; ribs on the truncation have a few scattered spinose nodules; ribs flat, those anterior to the truncation having the flat tops sloping anteriorly, thus giving the ribs an asymmetric V-shaped cross-section. There are nine ribs on the truncation, and fourteen on the main body of the shell. Concentric threads in the interspaces, which, in the anterior part of the shell occasionally cross the ribs. The nodules on the ribs are rather low and indistinct except on the rib which marks the trnncation, where they are prominent. Length 10 mm., height 11 mm., semi-diameter, etc., 5 mm. Localities.~204:, 52(a), 192, 77? (Berkey). Horizon.—Qnebradillas limestone (characteristic), and in the Ponce limestone. Cardium (Trigonocardia) haitense Sowerby variety areciboense, new variety Plate XIX, Figure 9 Very close to C. haitense cercadicum Maury, but shorter and more ^liarply trnncate, and with fewer, coarser ribs which are more de- 118 SCIENTIFIC SURVEY OF PORTO RICO cidedly angular. The ribs on the truncation near the dorsal margin have regularly spaced V-shaped spines, pointing sharply upward. The nodules and concentric threads are otherwise exactly like those of variety cercadicum. There are six ribs on the truncation and eleven on the remainder of the shell. Length 10 mm., height 14 mm., semi-diameter 6 mm. Locality,—204. Also Berkey 77. Horizon.—Abundant in the Quebradillas limestone and occurring also in the Ponce limestone. Genus dementia Gray Clementia dariena Conrad Plate XIX, Figures 10, 11, 12 Meretrix dariena Conrad, Pac. R. R. Rep., V, p. 328, PL G, fig. 55, 185G. Clementia dariena Gabb, Jour. Acad. Nat. Sci. Phila. (2) VIII, p. 344, PL 44, fig. 16, 16a, 1881. Clementia dariena DaU, Trans. Wag. Inst. ScL, III, pt. 6, p. 1235, 1903. Clementia dariena Tonla, Jahrb. der K. K. GeoL Reichanst. Wien, LVIII, p. 725, PL 27, figs. 9, 10, 1908. Clementia dariena Brown & Pilsbry, Proc. Acad. Nat. Sci. Phila., p. 371, PL 28, fig. 1, 1911. The typical Porto Rican shells are smaller than tliose of the Panama region and Costa Eica, but otherwise show no marked dif- ferences. The Porto Rico shells are not dwarfed forms, but merely arrested in growth, the average adult being an exact replica of a Gatun shell when the latter is two-thirds grown. This might lead to the supposition that the Porto Eican analogue is a primitive form of the Gatun shell, except for the fact that the former occasionally reaches a size as great as the average Gatun shell and is exactly similar, even to the loss of ribs near the ventral margin. To em phasize ttis point, an average specimen from Dr. Kemp's Gatiiii collection (in the Columbia University museum) is illustrated heiv together with one of the large Porto Rican shells, for comparisois. A comparison of the Porto Rican shells with available sources i-^ shown in the following table. HUBBARD, TERTIARY MOLLUSCA FROM LARES DISTRICT 119 Table 2 Source Length mm. Height mm. Diameter mm. Number of prominent ribs Breadth of ventral ribless zone mm. (meas. vertical) Gabb, illustration. Sapote, Costa Rica 57 47.5 33.5 26-35 10 Brown & Pilsbry, illustra- tion. Gatun 65 63 ? 26? 18 Toula, illustration. Gatun. . 67 56 ? 28 19 1 Toula, description. Gatun. . 47 38 ? ? ? Kemp collection, specimen. Upper Gatun 63 61.5 36 33 23 Kemp collection, specimen. Lower Gatun 51 43 25.5 31 ^ do 48 44 24.5 30 10 do (young shell) 27 25? 14 22? Porto Rico, San Sebastian shale at Collazo Falls .... 48 44.5 26 27 13 Porto Rico, San Sebastian calcareous shale at Robles. 41 34 19 25-30 do 39 31 23 do 38 33.5 20 do 38 35.5 18.5 do 37.5 33 19.5 do 35 32.5 20 do 35 32.5 17.5 0-5 do 35 33 17 do ? 34 20 15 do ? 33 do. . . ? 32 20 do ? 29 17.5 do ? 28 19 i __ _ 120 SCIENTIFIC SURVEY OF PORTO RICO It will be noticed from this table that there is considerable varia- tion in size and proportions among the specimens. This is due in part to distortion by pressure as regards the proportions. If the average of these measurements is taken and the height and diameter expressed in terms of the length as unity, we have the following relationship : Length Height Diameter Average length mm. Gabb's illustration. S a p o t e, Costa Rica 1 0.83 0.59 57 Kemp's large specimen from the upper Gatun 1 0.98 0.57 63 Kemp's smaller specimens from the lower Gatun... 1 0.88 0.51 42 Large Porto Rico specimen from the Collazo district 1 0.93 0.54 48 Smaller Porto Rico specimens from the Robles district 1 0.87 0.51 37 It will be noticed that in the larger specimens there is a relatively greater increase in the height and diameter, due to the slight change in shape of the shell with growth. The measurements from Gabb's illustration are of doubtful value in this comparison. The uniformity of size and number of ribs is a feature brought out in the table. The Porto Rican shells have about the same number of ribs as the Gatun shells, and in the ribbed stage are about the same size. The Gatun shells usually, and the Porto Eican shells occa- sionally grow beyond this stage with loss of ribs, an ontogerontie character. The Gatun shells were longer lived, apparently living under more favorable conditions than those of the upper San Sebas- tian shale in Porto Eico. Localities,—2Z2{V), 233, Collazo Falls, 83, 84, Juana Diaz. Horizon,—San Sebastian shale, Juana Diaz shale. Genus Oytherea Bolten Cytherea (Oytherea) berkeyi, new species Plate XX, Figures 1, 2, 3 Shell large, convex, very inequilateral; right valve v^lth two posterior bifid and one anterior simple cardinal teeth; left valve with one middle hifi^l and anterior and posterior simple cardinals; left anterior papilliform small HUBBARD, TERTIARY MOLLUSGA FROM LARES DISTRICT 121 out distinct; adductor scars and pallial line strongly impressed, the latter granulose; pallial sinus large, broad, rounded, ascending; inner margins minutely crenulate; small auxiliary adductor scars, situated close to dorsal margin between beaks and principal anterior adductor scars, and nearer to the latter; obscure, irregular impressed line in interior of each valve, descends vertically from anterior end of beak and dies out midway between beak and ventral margin; surface of valves marked by numerous small radial ribs, somewhat wavy, evenly spaced, and fairly uniform in size, but becoming coarser over the posterior third of the shell, where they alternate in strength, with occasionally two or three small ribs alternating with one lagrer one; the whole cut by fine, low, sharp, raised concentric lamellae, evenly spaced near the beaks, but gradually increasing to 2, 3, or 4 mm. apart toward the ventral margin, where they suddenly become irregularly spaced and crowded, apparently a gerontic character. These concentric lamellae are delicately fluted by the radials in the umbonal region. Minute growth lines cross the sculpture between the lamellae. The concentric sculpture is nowhere as prominent as the radial which increases in coarseness ventrally. The largest specimen, an internal mold collected by Dr. Berkey, measures in length 85 mm., height 68 mm., diameter 48 mm. A large shell of the same type as C. tarquinia Dall and also resem- bling G, lacerata Ilanley, a recent shell from China, and (A antiqua King, recent, from Chile and Patagonia. It differs from all of these in having the radial sculpture predominate over the concentric scnlpture. Localities.—318, 41, 78, 98(Berkey). Bayamon and Ponce (Lobeck). Horizon.—Quebradillas limestone Ponce limestone. Genus Pitaria Romer Pitaria (Hyphantosoma) carbasea Guppy Plate XVI, Fignre 2 Gytherea {Circe) carhasea Guppy, Quart. .Jour. Geol. Soc, XXII, p. 292, PI. 18, fig. 13, 1866. Gallista carhasea Gabb, Trans. Amer. Phil. Soc, XV., p. 250, 1873. Pitaria {Hyphantosoma) carhasea Dall, Trans. Wagner Inst. Sci., Ill, pt. 6, p. 1266, 1903. This shell occurs abundantly as internal molds, but only one frag- ^nent of external mold was found showing the delicate sculpture. I he pallial sinus is sub-angular, deep, reaching nearly to the middle *^t* the valve; interior of shell smooth; exterior surface marked by ^^Tie, somewhat wavy or irregular concentric lamellae crossed by fine 122 SCIENTIFIC SURVEY OF PORTO RICO divaricate lines, strongest anteriorly, and forming two zigzag zones near the middle of the valve. These divaricate lines, when viewed under a lens are seen to consist of rows of pits in the lamellae; hinule large, demarked by fine sharp impressed line, and crossed faintly by the concentric lamellae, thus being rendered indistinct. The shells vary considerably in size, the largest internal mold measuring in length 32 mm., height 26 mm., diameter 16 mm. Type localities.—64, 225. Other localities,—Q19, 233, 343, 232(b). Ilange.—San Sebastian shale, Lares limestone, and Cibao lime- stone. Abundant in the Cibao limestone. Genus Chione Megerle von Miihlfelclt Ohione woodwardi Guppy Plate XIII, Figure 7 Venus Woodwardi Guppy, Quart. Jour. Geol. Soc. London, XXII, p. 292, PI. 18, fig. 1, 1866; Idem. XXXII, p. 530, 1876. Chione Woodwardi Dall, Trans. Wagner Inst. Sci., Ill, pt. 6, p. 1291, 1903. Chione Woodwardi Maury, Bull. Amer. Paleont., V, No. 29, p. 218, PI. 37, fig. 6, 1917. This is one of the most abundant fossils in the Quebradillas lime- stone. The shells show no differences from those described from Jamaica and Santo Domingo. Localities—204:, 217, 52(a), 670, 179, 225. Near Bayamon (Semmes and Lobeck). N'ear Guanica Central (Lobeck). Vieques Island (Lobeek). 77 (Berkey). Culenbrinas Point, Ponce, and K. 2.4 Ponce-Adjuntas road (Mitchell). Horizons.—Lares limestone ?, Quebradillas limestone. Ponce lime- stone. CMone (Lirophora) hendersoni Dall Venus papfiia Guppy, Quart. Jour. Geol. Soc. London, XXII, p. 292, 1860. Not of Linn6. Chione paphia Gabb, Trans. Amer. Phil. Soc, XV, p. 249, 1873. Venus paphia Guppy, Geol. Mag., decade 2, I, p. 442, 1874, etc., ex parte.: Quart. Jour. Geol. Soc, XXXII, p. 530, 1876. HUBBARD, TERTIARY MOLLUSCA FROM LARES DISTRICT 123 Ghione (Lirophora) hendersoni Dall, Trans. Wagner Inst. Sci., Ill, pt. 6, p. 1295, PI. 55, fig. 22, 1903. Ghione (Lirophora) hendersoni Maury, Bull. Amer. Paleont, V, No. 29, p. 219, PI. 37, fig. 8, 1917. The Porto Rican shells are apparently closer to the Santo Domingo than to the Bowden shells. The specimens show the obscure crennla- tion at base of ribs, and the sudden thickening of the ribs over the anterior portion of shell. There are eleven or twelve large, widely spaced ribs. They are obsolete in the umbonal region. Interior of shell has deeply impressed pallial line and adductor scars; pallial sinus short and angular. An average specimen measures in length 31 mm., height 22 mm., diameter 14.5 mm. The largest measures in length 36 mm., height 27 mm., semi-diameter 8 mm. Localities.—179, 331, 343, 64, 619 ?. Range,—Lares limestone to Los Puertos limestone. Grenus Tellina (Linne) Lamarck Tellina strophoidea, new species Plate XX, Figures 4, 5 Shell moderately elongate, sub-equilateral; beaks inconspicuous; surface with numerous elevated, sharp concentric lamellae, which, on adult specimens, frequently merge on the posterior part of shell into fewer, coarser lamellae; numerous radial striae can be seen under a lens in transverse light. Ven- trally they are interrupted by the lamellae, but toward the beaks they become more distinct and continuous, so that on the nuclear portion of the shell they are nearly as strong as the concentric sculpture, resulting in an extremely line cancellate ornamentation; posterior slope with two radial folds and a moderately deep sulcus between. The upper fold is narrower and less pro- nounced; posterior dorsal margin marked by accentuation of the lamellae into a slight ridge. In the adult shells the lowest fold is, in the right valve, 'louble, with a slight sulcus between. This is only noticeable at the distal ' nd of the fold. The lamellae bend sharply upward on crossing the lower 'old; lunule extremely narrow; interior of shell unknown. Length 48 mm., '1 eight 27 mm., semi-diameter 6 mm. This shell is nearest to T, strophia Dall, which it resembles in iilpture, but is considerably, less elongate. Localities.—204:, 216, 98(Berkey). lU/nge,—Throughout the Quebradillas limestone. 124 SCIENTIFIC SURVEY OF PORTO RICO Tellina portoricoensis, new species Plate XX, Figure 6 Shell resembling T, strophoidea but with much finer concentric sculpture. Shell sub-equilateral, slightly convex; beaks low; surface with fine, sharp, hardly raised concentric lamellae, at first uniform and evenly spaced, but ventrally becoming slightly irregular, with every fifth or sixth one more prominent than the others; low, inconspicuous double fold on the umbonal ridge, becoming almost obsolete distally, and over which the concentric lamellae are flexed sharply upward in crossing; fine obscure growth lines between the lamellae; faint radial rays seen only in oblique light; interior of shell unknown. Length 42 mm., height 23 mm., semi-diameter 5 mm. Locality.—204. Horizon,—Quebradillas limestone. Tellina (Scissula) grabaui, new species Plate XVT, Figures 3, 4 Shell small, elongate, slightly convex, sub-equilateral; anterior rounded, posterior roundly truncate; surface with fine growth lines, periodically in- cised, replaced on the umbonal ridge by widely spaced, sharp concentric lamellae, which cross a faint sulcus above the umbonal ridge and, decreasing in size and strength, continue to the dorsal margin; growth lines crossed by faint, wavy oblique lines, becoming more distinct as they approach the umbonal ridge, where they end suddenly, in contact with the concentric lamel- lae. These oblique lines begin near the anterior margin and slope downward toward the posterior. Interior of shell unknown. Length 20 mm., height 11 mm., semi-diameter 2.5 mm. This shell is close to T. (Scissula) lampra Dall, of the Chipola Oligocene. It is also close to T, rowlandi Toula, a species from the Gatun formation. T, caribea d'Orbigny seems to be the living rep- resentative of these shells. 2\ (Scissula) cercadica Maury, a shell from the Santo Domingo Oligocene, is a similar but less elongate form. Locality,—204. Horizon.—Quebradillas limestone. TeUina, species aff. T. (Angulus) atossa Dall Plate XI, Figure 7 A single left valve of a Tellina of uncertain identity. Slu^^ moderately convex, showing prominent lateral teeth; surface witii HUBBARD, TERTIARY MOLLUSCA FROM LARES DISTL F 125 fine sharp concentric lamellae, strongest near the ventral margin, and obscure growth lines between the lamellae. The latter are ac- centuated on the anterior slope; shallow radial sulcus located next to the posterior dorsal margin. Interior of shell unknown. In out- line and general appearance, it resembles T, (Angulus) atossa of the Tampa Silex beds. Length about 20 mm., height 14 mm., semi- diameter 4 mm. Locality.—204. Horizon.—Quebradillas limestone. Genus Metis H. and A. Adams Metis trinitaria Dall Plate X, Figure 7 Metis trinitaria Dall, Trans. Wagner Inst. Sci., Ill, pt. 5, p. 1041, PI. 46, fig. 24, 1900, cf. Tellina Uplicata Guppy, Quart. Jour. Geol. Soc, XXXII, p. 530, 1876. Not of Conrad. Metis trinitaria Maury, Bull. Amer. Paleont., V, p. 226, 1917. The specimens differ somewhat from DalFs description, being more nearly equilateral, and the pallial sinuses of the two valves being subequal and of equal height. The shell seems to be quite variable, however. Ventral margin arcuate, with broad median sinus in the right valve; sharp, rounded posterior fold with a second '»l)scure fold higher up; surface marked by growth lines and faint radial striations, the latter fading out toward the lateral margins. There is some variation in the size and proportions as shown by the {'allowing measurements of internal molds: Length 52 mm., Height 44 mm., Diara. 23 mm. Length 54 mm., Height 44 mm., Diam. 19 mm. Length 48 mm.. Height 39 mm., Diam. 16 mm. Some internal molds of this shell, collected in Porto Eico in 1915 Dr. D. R. Semmes, were shown to Dr. Dall, who identified them M. trinitaiia. This species is reported from Trinidad and Cuba, i doubtfully from Santo Domingo. Specimens from Sombrero, 126 SCIENTIFIC SURVEY OF PORTO RICO W. I., in the Columbia University collections seem to be of this species, but are considerably larger than the Porto Rican shells. Localities,—204:, 678, 61, 319, 801. 98(Berkey). San Juan district (Semmes). Culebrinas Point (Mitchell). Horizon.—This shell is the chief horizon marker of the Quebra- dillas limestone along the north coast. The internal molds are found in great numbers in many localities. It occurs rarely in the Los Puertos limestone, and Ponce limestone. Genus Solen Linne Solen (Plectosolen) coUa^oensis, new species PLato XI, Figure 8 Shell produced anteriorly, with beaks 7.5 mm, behind the anterior margin; both ends roundly truncate; height slightly less in middle of shell than at the ends; beaks inconspicuous; surface marked only by growth lines, strengthened on anterior slope, and a narrow furrow extending from the beaks to the anterior-ventral corner. Length 42 mm., height 11 mm., diameter 6.5 mm. This is a small straight shell of the section Plectosolen, having a strong resemblance to the Eocene forms of the Paris Basin, such as S, plagiaulax Cossmann, and 8. laversinensis Lef. and AVat. It is probably of the type of S. ohliquus Sowerby. It also resembles a small S. ohliquus Spengler, but is a true Plectosolen. The description is based on a single specimen from the black shale at Collazo Falls. The specimen is badly fractured, though nearly complete. Localities.—261, Juana Diaz, Yauco. Horizon.—San Sebastian shale, Juana Diaz shale. Genus Psammosolen Risso Psammosolen sancti-dominici Maury Psammosoleyi sancti-dominici Maury, Bull. Amer. Paleont., V, No. 29, p. 22*^ PL 37, fig. 13, 1917. Only two fragments were found, but the marking is distinct an characteristic, and leaves no doubt as to the identity. One speciuK seems to be about the same size as the Santo Domingo specimen HUBBARD, TERTIARY M0LLU8CA FROM LARES DISTRICT 127 described by Maury. The other specimen is smaller. The broad median sulcation is barely noticeable. Locality.—204. Horizon,—Quebradillas limestone. Genus Semele Schumacher Semele, species indet. SheU equivalve, nearly equilateral; beaks low; ends of shell rounded; anterior and posterior dorsal margins make angle of 125°; umbonal ridge low, obscure; escutcheon long and narrow; lunule short, and same width as the escutcheon; surface sculpture of fine, even, sharp concentric lamellae; about fourteen to every 10 mm.; no radial striation visible. Length 35 mm., height 30 mm., diameter 14 mm. This may be a new species, but the specimens are poor and do not permit an exact description, being known only from internal molds and a few fragments of external mold. The sculpture is finer than that of S. claytoni Maury. The shell resembles ^S. chipolana Dall, but is more elongate. Locality.—225. Horizon.—Lares limestone. Genus Thrachia Blainville Subgenus Cyathodonta Conrad Cyathodonta reedsi Maury Shell equivalve, sub-equilateral, moderately convex; anterior dorsal slope slowly descending, anterior rounded, posterior roundly truncate; sculpture of about twenty-five rounded to sub-angular concentric ripples, markedly wavy or irregular, and owing to the thinness of the shell, equally strong in 'he internal molds. The ripples have a strong tendency to become oblique 'H the anterior third of the shell; umbonal ridge low, rounded, beyond which lie ripples die out, leaving the posterior dorsal smooth except for growth 'ines. A right valve shows a low obscure radial fold about one-third the istance from the umbonal ridge to the dorsal margin; beaks rather high inl strongly incurved. Gerontic individuals show a complete loss of con- »'ntric ripples in the final stages of growth. Adult shell measures in length '' mm., height 19 mm., semi-diameter 6 mm. This shell is apparently uearest to C. gatunensis Toula but is more 128 SCIENTIFIC SURVEY OF PORTO RICO elongate, more nearly equilateral, and the smooth posterior slope higher and more produced. It is not as convex as the Gatun shell. Type Locality,—204. Other locality.—226 I Range,—Lares ? limestone to Quebradillas limestone. Genus Oorbula Lamarck Gorbula collazica Maury Localities,—CoUazo Falls, and doubtfully at 120 and 225. Horizons.—Typical of the San Sebastian shale^ and occurs doubt- fully as high as the Lares limestoue. Genus Teredo Linne Teredo incrassata Gabb Kuphus incrassatus Gabb, Trans. Amer. Phil. Soc, XV, p. 246, 1873; Jour. Acad. Nat. Sci. Phila., new ser., VIII, p. 342, PI. 44, fig. 12a-e. Teredo flstulaf Guppy, Quart. Jour. Geol. Soc, XXXII, p. 529, 1876. Teredo incrassata DaU, Trans. Wagner Inst. Sci., Ill, pt. 6, p. 1587, 1903. Teredo incrassata Maury, Bull. Amer. Paleont., V, No. 29, p. 235, PI. 39, fig. 24, 1917. The tubes vary in diameter, bnt average 20 mm. They attain considerable length, but are usually found broken in short pieces. Localities.-—m^ 10, Collazo Falls, 758, 162, 182, 179, 332, 619, 621, 616, 225, 23, 335, 330, 324, 74, 370, 749(a), 334. Horizons,—San Sebastian shale, Lares limestone, Cibao limestone, Los Puertos limestone, Quebradillas limestone. Extremely abundant. Outside the Lares District, this species has been found by Lobeck on Vieques Island (south and east sides), and in basal Tertiary be<N near Yauco, P. R. It has been found by Berkey at localities KA and 78, and by Mitchell in the Ponce formation and Juana Dij'/ shale. Genus Dentalum Linne Dentalium, species indet. Shell long, slender, nearly straight, slowly tapering, circular in cvo >- section; shell thick, the aperture being only about one-half the diameter < the tube; surface polished, and marked with numerous fine, very regu^ '» HUBBARD, TERTIARY MOLLUSGA FROM LARE^ DISTRICT 129 longitudinal tlireads, visible only under a hand lens and transverse light. The threads appear, under a lens, to be minutely beaded, but under a micro- scope, this appears to be the lesult of fine raised concentric growth lines, strongest in the interspaces between the longitudinal threads. There are about one hundred longitudinal threads on a tube of 1 mm. diameter. The shell structure is strongly fibrous, the fibrous striations appearing on the longitudinal threads as seen under the microscope. The apex is not shown in any of the specimens. The largest fragment, with a diameter of 1 mm. measures 13 mm. in length. The tapering of the tube is hardly discernible in this length. Many fragments were fonnd in the lower black sliale of a minute Dentalium, the largest of Avhicli is only abont 1 mm. in diameter, and the majority of which average less than % mm. Locality,—2G1. Horizon.—San Sebastian shal(\ Genus Calliostoma Swainson Calliostoma portoricoensis, new species Plate XXT, Figure 1 Whorls seven, including a rather high protoconch of two smooth, round whorls; remaining whorls flat; suture narrow but deeply impressed; surface of whorls with six spirals and strongly marked oblique growth lines which cut the spirals, giving them a wavy appearance. The five uppermost spirals are small, sharply raised, with wider concave interspaces. The two spirals immediately below the suture are somewhat smaller and show a tendency to group together. The sixth spiral, immediately above the suture, is very much larger, broad, and bluntly rounded, and forms the peripheral keel; base with eight prominent, broad, fiat spirals and fine raised oblique growth lines crossing the spirals and grooves between. Aperture and umbilical area not visible in the specimen. Length 11 mm., diameter 9 mm. A single specimen was found of a CaJfiostoma remarkable for ils elongate conical base (more than two-thirds jis long as the spire). Locality.—^204-. Horizon .—Quebradillas limestone. Genus Turbo Linne Turbo fetkii, new species Plate XXI, Figure 2 Shell small; whorls six; the first two flat topped, strongly keeled; the laaining whorls sub-round, but with slight angulation and broad flat 130 SCIENTIFIC HVnVEY OF PORTO RICO shoulder, nearly one-third the axial width of the whorl; suture deeply channelled; rounded spirals of two to three different sizes, increasing by intercalation, with total of about twenty on the body whorl, and of these five are very prominent; entire surface crossed by oblique incremental lines, strongest between the spirals; spirals and incremental lines visible in the sutural channel. Height 13 mm., diameter 11 mm. The above description is based on a single specimen, in which the anterior portion of the body whorl is missing. The shell is remark- able for its extremely deep^ squarely channelled sutnre. The spirals are smooth or with microscopic crennlation produced by the crossing of the growth lines. The spiral anterior to the suture is never promi- nent. This shell is like T. rhectogrammicus Dall, of tlie Florida Pliocene, but differs from the latter chiefly in its smaller size and its deeply channelled suture. Its suture is like that of T. spengleriaiius Gmelen, a recent shell from the West Indies, but the latter is much larger and has more spirals. This shell is named in honor of Dr. 0. R. Fetke, who lias worked on the Geology of the eastern end of Porto Rico. Locality.—313. Horizon.—Quebradillas limestone. Turbo dominicensis Gabb variety quebradillensis, new variety Shell larger than the Santo Domingo variety, T. dominicensis laloi Maury. the internal mold measuring in height (with tip of spire missing) 37 mm., maximum diameter 33 mm. Like the Santo Domingo variety, the final whorl is angulated, as presumably are the earlier whorls, though this cannot be ascertained from the specimen. It is more like Gabb's type, however, in having the majority of the spirals crenulate. On the final whorl the spiral anterior to the suture is more strongly crenulate than the others. Anterior to this, on the shoulder, are four minor crenulate spirals, the two central ones being slightly more prominent than the other two. At the shouldti angulation is a very strong, plain spiral, which projects sharply upward above the surface of the shoulder. The remainder of the whorl is orn;*- mented with eight or more strong simple spirals, each alternating with a single minor crenulate spiral. The basal portion of the whorl is not P" served. From the small portion visible in the specimen, it seems that tiu' ornamentation of the earlier whorls is similar, but with fewer spirals. T n' outer lip is lirate for a short distance, there being thirteen lirae and a P' ^" terior notch below the shoulder angulation. This shell was found among the material collected by Dr. Lob* 1^^ in the Qixebradillas limestone near Bayamon. It consists of a sin^^* HUBBARD, TERTIARY M0LLU8CA FROM LARES DISTRICT 131 internal mold and a portion of the external mold of the same speci- men^ which shows the sculpture of the final whorl and a small por- tion of the spire. A few internal molds, possibly of the same species were found in the Quebradillas limestone of the Lares district. Locality.—N'ear Bayamon (Lobeck), 204? llorizon.-—Quebradillas limestone. Genus Liotia Gray Liotia (Arene) coronata Dall variety portoricoensis, new variety Plate XXT, Figure 3 Shell small, five whorls, including flat, smooth naticoid protoconch of two whorls. Two spiral keels appear on the third (or first post-nuclear) whorl. A third spiral appears on the fourth whorl just above the suture; suture deeply channelled; shoulder of third and fourth whorls marked by fine beaded spiral ridge immediately below the suture. Fine growth lines crossed the shoulder and produce a slight beading of the uppermost spiral keel; final whorl smooth except for strongly incised growth lines, which are stronger than the almost obsolete spirals. The final whorl tends to lose the coiling habit, becoming almost free from the preceding whorl. Only a single specimen was found, and the aperture and base of the shell are unknown. Height 5 mm., diameter 5 mm. The first four whorls of this shell are quite similar to DalTs 1'ampa species. In the Porto Eican shell the longitudinal wrinkles, <'haracteristic of the Tampa shell, become obsolete on the fourth whorl, but reappear strongly on the last whorl. The Porto Kican \ ariety seems to have been derived from the Tampa species, and is ;!ii interesting example of a phylogerontic form. Locality,—204. llorizon.—Quebradillas limestone. Genus Xenophora Fischer de Waldheim Xenophora conchyliophora (Born) 'ihus cofichyliophorus Born, Mus. Caes. Vind. p. 333, 1778. ^<hus aggliitinans Lamarck, Anim. sans Vert., VII, XIV. '>rus agglutinans Gabb, Trans. Amer. Phil. Soc, XV, p. 241, 1873. 132 SCIENTIFIC SURVEY OF PORTO RICO XenopJiora conchyliophora Dall, Trans. Wagner Inst. Sci., Ill, pt. 2, pp. 360- 362, 1892; Bull. 90, U. S. Nat. Mus., p. 105, PI. 15, figs. 1, 3, 1915. Xenophora conchyliophora Maury, Bull. Amer. Paleont., V, No. 29, p. 133, PI. 23, fig. 7, 1917. The Porto Eican specimens show no differences from the typical forms of this species. Localities.—20^, 225, 24. Range.—Lares limestone to Quebradillas limestone. Very abun- dant in the Quebradillas. Genus Neritina Ijamarck Neritina (chipolana varJ) collazoensis, new species Plate XXI, Figure 4 Shell small, fragile, polished, with low spire, and apparently three whorls, A single specimen was obtained, in which the spire has been crushed and the aperture is not visible. The outline of the shell and the surface mark- ings are like N. chipolana Dall, but with the markings more crowded and numerous, and all being discontinuous. These lines show, however, the same arrangement in groups of three or four, with zig-zags and curves. The curves are frequently convex in opposite directions in adjacent lines, leaving circular areas between the lines, a feature which is also characteristic of the Chipola species, judging from Ball's illustration (Wagner Inst., Ill, pt. 4, PL 23, fig. 19, 1898). The lines are very narrow, and a dark reddish purple in color. The shell is slightly smaller than the Chipolan form, the height being 4 mm. and the maximum diameter 4,5 mm. In places where the epi- dermis has been chipped off, exceedingly fine and very regular growth lines may be seen with a lens. This shell was obtained from a stratum of lignitic shale in the Collazo Falls section, and is associated with fossil leaves and minute, thin-shelled bivalves, apparently fresh water forms. This stratum is intercalated in marine beds, and is of interest in showing the eon ditions existing in this locality during deposition of the San Sebas tian shale. Locality.—261. Iloiizon.—San Sebastian shale. Genus Hipponyx Defrance Hipponyx portoricoensis, new species Plate XXT, Figures 5, 6 Shell small, obliquely conical; apex at or near posterior extremity, oft< overhanging, and slightly recurved; surface with irregular bifurcating radi HUBBARD, TERTIARY MOLLUSGA FROM LARES DISTRICT 133 ribs and less prominent fluted concentric lamellae; Interior with faint but large horse-shoe shaped scar. This shell is very variable, but in all specimens the apex is blunt and rounded. Some specimens show hardly any recurvature to the apex, while in others this feature is marked, and in all cases it is to be left. A strongly recurved specimen measures in diameter of aperture about 7 mm., height of apex above base 4 mm. A low flat shell without curvature measures in diameter 10 mm., height of apex 3 mm. The largest specimen measures in diameter 11 mm., height of apex 6.5 mm. Localities.—204., 220, 23 I Range.—Los Puertos limestone to Quebradillas limestone. Genus Oalyptrsea Lamarck Calyptrsea cf . centralis Conrad Infundibulum centralis Conrad, Am. Jour. Sci., XLI, p. 348, 1841; Med. Tert., p. 80, PI. 45, fig. 5, 1845. Trochita centralis Emmons, Geol. N. C, p. 276, fig. 193, 1858. Infundibulum concentricum H. C. Lea, Trans. Amer. Phil. Soc, (2), IX, p. 249, PI. 35, fig. 39, 1845 (young sheU). Grochita collinsii Gabb, Jour. Acad. Nat. Sci. PhUa., (2), VIII, p. 342, PI. 44, figs. 11, 11a, 1875. Infundihulum candeanum d'Orbigny, MoH. Cuba, II, p. 190, PI. 24, figs. 28. 29, 1842. Galerus candeanus DaH, Hemphiirs Shells, p. 335, 1883. Galerus parvulus Dunker, Jahrb. Deut. Mai. Ges., p. 244, 1875. Galyptrea candeana Dall, Blake Rept., p. 284, 1889. Galyptrea centralis Dall, Trans. Wagner Inst. Sci., Ill, pt. 2, p. 353, 1892. A single external mold was found which is apparently this species. Diameter of base 8 mm., height of apex 4 mm. Locality.—204. Horizon.—Quebradillas limestone. Genus Crucibulum Schumacher Crucibulum auricula Gmelin variety portoricoensis, new variety Plate XXI, Figures 7, 8 Cup typical of 0. auricula Gmelin. Surface with fine, irregular, dichoto- ^^s radial lines, crossed by fine wavy growth lines. Form varies from 134 SCIENTIFIC 8URVEY OF PORTO RICO high, acute apex to low apex with broad base. Cup uniform in size and shape in all the specimens. A shell with low apex measures in diameter of base 20 mm. height of apex 7 mm. Localities.—204. (also Berkej 98). Horizon,—Quebradillas limestone (fairly abundant). Crucibulum auricula? variety Plate XXI, Figure 9 This is probably one of the many variations of C, auricula. Only a few fragmental specimens were obtained, and the interior is un- known. Apex sub-central; coarse radial ribs, somewhat irregular, bifur- eating and trifurcating. Diameter 14 mm., height of apex 6 mm. Locality.—204. Horizon,—Quebradillas limestone. Crucibulum (Dispotaea) collazum, new species Plate XXI, Figure 10 Shell small, smooth; apex eccentric, sharp, strongly gyrate in the normal direction; basal margin sub-circular, with large rounded sinus on the side below the apex. On either side of the sinus the margin flares, or flattens out, and is thickened, being analogous to the thickened outer lip or varix of coiled gastropods; cup large, deep, and about one-half free from the shell wall. Most of the free half has been broken away in the specimen illustrated, but when perfect, it has a tortuous, or S-shaped curvature, and overhangs the apex cavity, being suggestive of the internal appendage of a Calyptrwa. Diameter of aperture 7 mm., height of apex 4 mm. Two specimens were collected, both showing the marginal sinus, which is therefore assumed not to be an accident of growth. The shell illustrated appears to be an adult specimen. The other shell is smaller, with a correspondingly smaller marginal sinus. Localities.—84, 261. Horizon.—San Sebastian shale. Genus Natica Scopoli Natica canrena? (Linne) Moerch Nerita canrena (Linn^ in part) Auct., Moerch, Malak. Blatt., XXIV, p. 62, 1S7 Natica canrena Gabb, Trans. Amer. Phil. Soc, XV., p. 223, 1873. HUBBARD, TERTIARY M0LLU8CA FROM LARES DISTRICT 135 Natica canrena Guppy, Quart. Jour. Geol. Soc, XXXII, p. 518, 1876. isfatica canrena Dall, Trans. Wagner Inst. Sci., Ill, pt. 2, pp. 364-365, 1892. Natica canrena Brown and Pilsbry, Proc. Acad. Nat. Sci. Phila., p. 508, 1912. Natica canrena Maury, Bull. Amer. Paleont, V, No. 29, p. 134, PI. 23, fig. 10, 1917. A small Natica was found which is probably the young of N. canrena. The specimen shows on the last whorl the faint oblique striations, which start at the suture. Diameter 7 mm. Several in- ternal moldsj possibly of this species, were found in the Oibao lime- stone at locality 22. The largest measures in height 22 mm., diameter 25 mm. Locality.—204. Horizon.—Quebradillas limestone. Natica (AmpuUina?) collazoensis, new species Plate XXI, Figures 11, 12 Shell large, moderately high spired; suture deeply Impressed; whorls six to eight; umbilicus partly covered by callus, or entirely open in some speci- mens, in which the callus may have been broken away. Some specimens show the last whorl strongly flattened below the suture, while in others the whorl is evenly rounded. This is probably a sex difference; shell thin; sur- face with numerous fine, impressed spiral lines, and much finer, almost microscopic growth line threads, periodically incised, marking a resting stage in the growth of the shell. The growth lines are remarkable for their even- ness. Largest specimen measures in height 6G mm., diameter, 52 mm. The shell in size and general apy)earanee resembles Anipullina ampliora Heilprin, and is probably related to the large Eocene forms. It has some resemblance to Natica species indet. Brown & Pilsbry (Proc. Acad. 'Nat Sci. Phila., p. 360, PI. 25, figs. 1, 2, 1911), a <»atun shell. Localities.—262, 265, 86 (base of falls), Collazo Palls, 264 fbot- um 3rd falls), 83, 235. Horizon.—San Sebastian shale, (very abundant). Genus Epitonium Bolten Epitonium (Cirsotrema) collazoensis, new species Plate XXII, Figures 1, 2 Shell with three and one-half whorls measures in height 25 mm., maximum <'^ meter 13 mm.; whorls rounded; suture distinct, but not deep; whorls ^^ h about twenty-four slightly oblique, moderately strong longitudinal ribs 136 SCIENTIFIC SURVEY OF PORTO RICO and two opposite rows of sub-continuous varices, the last varix being at the outer lip; longitudinal ribs fluted by another series of oblique ribs of equal strength, descending to the left at about 45°, continuing from suture to suture, and being more or less interrupted by the longitudinal series of ribs. At base of body whorl, both series of ribs terminate against a strong, rugose or rope-like spiral, which encircles the umbilical area, and is interrupted 5nly by the varices. Over the entire surface of the shell is a fine microscopic cloth- like texture composed of three intersecting series of threads, one series vertical, another parallel with the 45° ribs, and the third series descending to the right at about 45°. The three series are named in order of their relative strength, the vertical series being strongest, and locally obscuring the other two series. Aperture circular. In general appearance the shell is typical of the high spired forms of this group. A single decollate specimen was found of an Epitonium which is remarkable for its microscopic texture, which is somewhat of the nature of that of E. textuvestitum Maury, but the shell is quite diiferent from the latter. Apparently the nearest relatives of this shell are to be found in the Paris Basin beds. Two such forms, very similar, though smaller, are Cirsotrema subspinosum (Grat.) of the Aquitanien, and 0. bourgeoisi de Boury, of the Helvetian. This relationship is of considerable significance in considering the age of the San Sebastian shale. Locality.—K. 29.2-3 Lares road. Horizon.—San Sebastian shale. Genus Turritella Lamarck Turritella tornata Guppy variety portoricoensis, new variety Plate XXI, Figures le3, 14 Shell corresponds with Guppy's description, except that in the last few whorls the anterior keel is double, and there are frequently as many as four spiral threads in the median concavity. There are also from one to tw< threads on the shoulder and likewise on the slope below the lowrr keel. The base is spirally threaded and marked by accentuated growth lines. Th- beading of the spirals is lacking or obscure, due probably to the poor sta^ of preservation of the specimens. All specimens are decollate. The large- has a maximum diameter of 14 mm. and height (4 whorls) of 26 mm.; V- ' average sized specimen has a maximum diameter of 10 mm. This species is extremely abundant in the San Sebastian sha • Xearly all specimens are poorly preserved casts or internal moh' • and the ornamentation is difficult to make out. HUBBARD. TERTIARY M0LLU8GA FROM LARES DI8TRWT 137 Type locality.—2d2{h). Other localities.—226, 331, 333, 343, Collazo Falls, 226, 262, 83, 233. Range,—San Sebastian shale to Lares limestone. Turritella planigyrata Guppy T.planigyrata Guppy, Proc. Sci. Assoc. Trinidad, p. 169, 1867; Geol. Mag., p. 408, PI. 18, fig. 5, 1874. T. planigyrata Gabb, Trans. Amer. Phil. Soc, XV, p. 240, 1873. T. planigyrata Guppy, Quart. Jour. Geol. Soc, XXXII, p. 519, 1876. T. planigyrata Maury, Bull. Amer. Paleont., V, No. 29, p. 129, PI. 22, fig. 14, 1917. A fragment comprising the last three whorls. Height 14 mm., maximum diameter 8.5 mm. The specimen agrees with the de- scriptions by Guppy and Gabb, and there seems to be no doubt of the identity. Locality,—234. Horizon,—San Sebastian shale. Turritella mitchelli, new species Plate XXII, Figure 8 A single decollate specimen with seven and one-half whorls. Shell large, high spired (apical angle 5°); whorls flat and continuous; suture indistinct or invisible; w^horls marked by three prominent crenulated spirals and 'ninor, minutely beaded spiral threads; the whole surface covered by minute si)iial striae and longitudinal growth lines, the latter producing the crenu- iation in the spirals. In front of each suture is a flat area, less than one-third the axial width of the whorl, marked by two to three obscure spiral threads; 'i^'xt in order come a single primary spiral, followed by two fairly prominent ^' condary spirals in the median portion of the whorl. The anterior third **' the whorl is marked by the two most prominent primary spirals with a li nrow channel between them, giving the effect of a doubled spiral band. i le anterior member of this pair is slightly larger than the other on the ^ -t two whorls. Of the microscopic sculpture above mentioned, the spiral - iae are the most prominent on the primary ridges, and obsolete in the '• f^rspaces, whereas the reverse is true of the growth lines, which results in '5 strongest beading being on the minor spirals in the interspaces. The '- •' is sulcated below the anterior primary spiral, and is moderately convex '^ erior to this sulcus. The surface of the base is marked only by the spiral ^ -le and growth lines, which here are markedly wavy or vermicular. The 138 SCIENTIFIC SURVEY OF PORTO RICO suture is distinct on the last two whorls, but on the spire it is invisible, being concealed by the anterior primary spiral, which overhangs it. Height 59 mm., maximum diameter 22 mm. As the protoconch and upper portion of the spire are missing, it is difficult to trace the relationship of this shell with other species. The succession and arrangement of spirals is similar to T. halensis Dall, a shell from the Flint River Oligocene. The finer sculpture and beading resemble T. altilira Conrad, of the Gatun formation, and T. calostemma Pilsbry & Brown, of the Oligocene of Haiti. This shell is undoubtedly a member of the T, tornata—T. altilira group, and is probably closest to T. calostemma, Berkey found a similar, and apparently related shell from the basal Tertiary near Juana Diaz. It differs in having four equally strong major spirals. This shell is named in honor of Dr. G. J. Mitchell. Locality,—Collazo. Horizon.—San Sebastian shale. Turritella portoricoensis, new species Plate XXI, Figure 15 Shell small; spire acute; about ten rounded whorls with about fifteen fine spiral threads with sub-equal intervals; suture distinct, but not channelled until the last three whorls; whorls at first evenly rounded with spiral threads of equal strength, but later becoming angulated by accentuation of spiral threads into a keel at periphery of whorl and another at anterior end of whorl, overhanging the suture; first three whorls loosely coiled; proto- conch missing on all specimens. The angulation begins at about the seventh whorl. A specimen with nine whorls measures in height 13 mm., maximum diameter 4 mm. The young of this shell has the whorls of T, plebeia Say, and in the adult, the whorls are like those of T. cequistriata Conrad, in some respects. The later whorls also resemble T, suhannulata acro- pora Dall, but are not quite as angular as in the latter species. TIh' nearest Antillean forms are T, planigyrata Guppy, of Santo Doming'*, and T. gatunensis Conrad, of Panama. The Porto Rican shell ^^ probably a less specialized member of this group. Locality.—204. Horizon.—Quebradillas limestone. HUBBARD, TERTIARY MOLLUSCA FROM LARES DISTRICT 139 Turritella berkeyi, new species Plate XXII, Figure 4 Shell extremely high spired, slender; whorls twenty-one; earliest whorls simple, with two keels of equal size; anterior and posterior slopes of whorls straight and of equal width; simple rounded median depression between the two keels; last ten whorls with the posterior keel becoming double and the shoulder of the whorl becoming gently convex, features which are quite promi- nent in the adult stage; beginning with the eighth or ninth whorl an obscure spiral appears on the anterior extermity of the whorl just above the suture and partially overlapped by the succeeding whorl; surface throughout i& lacking in ornamentation. Height 73 mm., maximum diameter 11 mm. This shell may possibly be a primitive form of T, perattennuaia Heilprin. It resembles T, alcida Dall, but is very much more slender. Other somewhat similar forms are T. altilirata Conrad, and T. variabilis variety alticosta Conrad. Locality.—204. Horizon,—Quebradillas limestone. Genus Petaloconchus Lea Petaloconchus domingensis Sowerby Petaloconchus domingensis Sowerby, Quart. Jour. Geol. Soc, VI, p. 51, PI. 10, fig. 8, a, b, c, 1849. Petaloconchus sculpturatus Gabb, Trans. Amer. Phil. Soc, XV, p, 240, 1873. Not of Lea. Petaloconchus sculpturatus Guppy, Quart. Jour. Geol. Soc, XXXII, p. 519, 1876. Vermetus (Petaloconchus) sculpturatus Dall (in part). Trans. Wagner Inst. Sci., Ill, pt. 2, pp. 305, 306, 1892. Petaloconchus domingensis Brown and Pilsbry, Proc Acad. Nat. Sci. Phila., p. 359, 1911. Petaloconchus domingensis Maury, Bull. Amer. Paleont, V, No. 29, p. 128, PI. 22, fig. 11, 1917. A single specimen was found, showing part of the coiled portion of the shell. There seems to be no doubt as to the identity. The fragment with three whorls measures in height 8 mm., diameter G. mm., diameter of whorl about 3 mm. Locality,—204. Horizon.—Quebradillas limestone. 140 SCIENTIFIC 8URVEY OF PORTO RICO Petaloconchus? coUazoensis, new species Plate XXI, Figure 16 Tube of small diameter (2.5 mm.); surface smooth except for faint growth lines; tip of spire missing in specimens, but one specimen shows a loosely, irregularly coiled cylindrical spire of five whorls; diameter of spire 10 mm.; whorls are in contact, but coiled with a 5 mm. radius, leaving large umbilical opening, the whole resembling the coiled steam pipes of a cylindrical boiler. The specimens show that the coiling habit ceases abruptly, the tubes then growing in all directions, almost tying knots. Localities,—263, CoUazo Falls. Horizon,—San Sebastian shale. Genus Pyramidella Lamarck Pyramidella portoricoensis, new species Plate XXI, Figure 17 Shell small, conic, smooth, rather low spired; seven flat whorls with sharp median spiral offset, forming, with the sharply beveled shoulder of the overlapping whorl, a broad, square sutural channel. The median offset, or angulation, continues around the body whorl; suture of earlier whorls is narrow; large circular perforation extends the entire length of the axis, and is very conspicuous as seen from the base; columella tri-plicate; posterior plication large and distinct; the other two small and obscure, of which the anterior one is situated at the extreme base of the columella; aperture oval; outer lip simple; height 4.75 mm., diameter 2 mm. This shell resembles P, (Longchwus) forulata Guppy, but its umbilicus places it with the typical group of Pyramidella, The suture is of the type of P. semicanaliculatus Maury. Locality.—204. Horizon.—Quebradillas limestone. Genus Modulus Gray Modulus modulus Linne variety basUeus Guppy Monodonta hasilea Guppy, Geol. Mag., new ser. decade 2, I, p. 434, PI. 16, fig 2, 1874. Modulus hasilea Dall, Trans. Wagner Inst. Sci., Ill, pt. 2, p. 294, 1892. Modulus modulus var. hasilea Dall, Trans. Wagner Inst. Sci., Ill, pt. 6, p. 158 1903. HUBBARD, TERTIARY MOLLUSCA FROM LARES DISTRICT 141 This shell is apparently the same as that described by Guppy from the Eowden. It agrees with Guppy's description^ especially in its low spire, and tuberculated, carinate whorls. On the lower portion of the final whorl, however, it apparently differs somewhat from the Bowden shell in having spirals of variable size, the primaries alter- anting with one or more fine secondary threads. Judging from Giippy's illustration, the aperture of the Porto Rican shell is broader. The outer lip is denticulate, but the interior is not preserved, so as to show whether the lirate character exists or not. Heiglit of shell is 14 mm., diameter 13 mm. Apparently the modern representative of this shell is M. lenticu- laris (Chemn.) Auct., which according to Tryon is synonymous with M. modulus Linne. Locality.—East side of Vieques Island (Collected by A. K. Lobeck). Horizon .— Quebradillas limestone. Genus Bittium (Leach M. S.) Gray Bittium species indet. Plate XXI, Figure 18 Whorls six (or more), with three raised spirals crossed by sharp ribs of equal height, and about twelve to a whorl; prominent nodes produced at intersections of ribs and spirals; suture deeply impressed; height (6 whorls) 11 mm., diameter 5 mm. A single specimen, too imperfect to identify or describe fully. Locality.—204. Horizon,—Quebradillas limestone. Genus Cerithium Adanson Cerithium portoricoensis, new species Plate XXII, Figures 5, (> Shell small, slender; protoconch unknown; whorls twelve or thirteen, ounded, with obscure varices of irregular occurrence on the last six whorls, nd usually a prominent varix on the body whorl; first three whorls witli iiee primary spirals crossed by about twelve narrow rounded ribs, more •ominent than the spirals, and slightly nodose where they cross the latter, ''''^^ whole producing a cancellate structure with rectangular pits; a fourth 142 SCIENTIFIC SURVEY OF PORTO RICO primary spiral appears on the fourth whorl; beginning with the sixth whorl, secondary, less prominent spiral threads appear, two immediately above the suture, and one between each of the four primaries. The two uppermost secondaries do not appear until the seventh whorl ; on last four whorls the ribs have increased to about twenty in number, are irregular, low, and obscure, be- ing marked chiefly by the lines of nodes where they cross the primary spirals. The ribs usually become obsolete on the anterior two-thirds of the body whorl; aperture short, slightly more than half the length of the body whorl; posterior canal small, U-shaped; anterior canal not quite covered by inner lip; outer lip slightly thickened; three average specimens have the following measurements: Height 20 mm.. Maximum Diameter 6 mm. Height 17 mm.. Maximum Diameter 5 mm. Height 16 mm.. Maximum Diameter 5 mm. This shell has a superficial resemblance to C, coccodes Dall, and to Clava chipolana Dall. Locality.—204. Horizon,—Quebradillas limestone (abundant). Cerithium quebradiUensis, new species Plate XXI, Figures 7, 8 A single decollate specimen with six whorls; earliest whorls roundly angular, with shoulder and peripheral keel; last three whorls with about 12 high, rounded ribs, sub-nodose at the keel; all whorls with primary spirals and secondary spiral threads; last four whorls with very fine tertiary spiral threads; earliest whorls show two closely grouped primary spirals at the keel, the upper one slightly stronger and forming the periphery of the whorl; a third primary occurs at (just posterior to) the suture; these primaries persist throughout, and a fourth primary spiral occurs on the base, being covered in the preceding whorls. It lies close to the suture; the secondary spirals at first form a group of three on the shoulder, another group of three below the keel, and a single one between the primary spirals of the keel. The three on the shoulder are markedly stronger than the other secondaries, a feature which persists throughout; on the third whorl (of the decollate specimen) the tertiary spiral threads appear, the first just above the sutural primary, the next ones intercalated between the secondaries in the group below the keel. The tertiaries do not appear on the shoulder until the fourtli whorl; the shoulder, adjacent to the suture, is, in all whorls, marked by i? rather wide band, at first smooth, but later marked by from one to six tertiar> threads; all whorls are marked by fine, raised growth lines, or longitudinal threads, which produce a minute beading on crossing the spirals, and whie- in the earlier whorls, produce with the spirals a fine cancellate ornament; tion; the primary spirals of the later whorls have a secondary superimpose • thread, which is beaded by the growth lines; the base is slightly concav HUBBARD, TERTIARY MOLLUSGA FROM LARES DISTRICT 143 and is sculptured with spirals of four sizes, more or less alternating. The single primary, above described, is sculptured with numerous minute spiral threads; pillar smooth, with no callus, anterior notch small, short, recurved; slight suggestion of a posterior notch; aperture ovate. Height 32 mm., diameter 15 mm. The most striking feature of this shell is the sudden change in the character of ornamentation of the whorls, with the appearance of the ribs. This final ribbed sculpture resembles that of C calli- soma Dall, from the Caloosahatchie Pliocene, but the Porto Rican shell differs from the latter in its concave base and general turritel- olid aspect. It is apparently not closely related to any species of the Antillean region. Locality,—204:, Horizon,—Quebradillas limestone. Cerithium (Campanile) collazum, new species Plate XXIII, Figures 1, 2 Shell large, conic, rapidly enlarging; whorls flattened to slightly rounded, with a median concavity in the later whorls of adult individuals; suture deeply impressed; each whorl with a flat, narrow shelf or shoulder pro- jecting beyond the preceeding whorl; surface of whorls with medium fine, nodose spirals like those of O. halense Dall, but with different arrangement. Just behind the suture are one to two very finely nodose spiral threads, one of which is frequently obscured by the overlapping whorl. Behind these is the largest spiral, ornamented with small round nodes about 2 mm. apart. The remainder of the whorl is ornamented with finer spirals, nodose, and alternating in size. The median concavity of the later whorls comes im- mediately posterior to the large noded spiral above described. The inter- spaces are slightly narrower than the spirals; base flattened, slightly convex, smooth; aperture roundly quadrate; columella stout, with single prominent fold, anterior notch short, large, recurved. A large decollate specimen with six whorls measures in height 48 mm., maximum diameter 28 mm. An interesting feature of this shell is the presence in the adult stage of an impressed spiral line near the periphery of the base, which marks the line of juncture with each succeeding whorl. This is an adult character, and is lacking in the earlier whorls. It is apparently an illustration of the inheritance of an acquired cliarac- ter. Another interesting feature is the change in form of the whorl from rounded in youth to flattened, and finally to a concave form in the final stages of old individuals. 144 SCIENTIFIC SURVEY OF PORTO RICO It would seem that this shell is related to some of the large, coni- cal forms from the Flint Eiver Oligocene, such as 0. halense Dall, as its ornamentation is quite similar to the latter. It differs notably in the shape of its whorls, and in this latter respect, is more like the large species of Campamile from the Paris Basin Eocene. Maury has described the internal mold of a larger, but similar shell from the San Sebastian shale Campanile (Portoricia) laricum Maury, which may be a related species or a variety. Maury's species differs chiefly in its flatter and more concave whorls, as well as in its considerably greater size. Localities.—262, CoUazo Falls, 142?, 236, 749(a). Range,—San Sebastian shale to lower Lares limestone. Genus Strombus Linne Strombus proximus? Sowerby StroTtibus proximus Sowerby, Quart. Jour. Geol. Soc, VI, p. 48, PL 9, fig. 8, 1849. Stromhus pugilis Gabb (in part), Trans. Amer. Phil. Soc, XV, p. 233, 1873. Not pugilis Linne. Exclude other synonyms. Stromhus proximus Guppy, Quart. Jour. Geol. Soc, XXXII, p. 521, 1876. 8 tromJ)US pugilis Dall (in part), Trans. Wagner Inst. Sci., Ill, pt. 1, p. 177, 1890. Not pugilis Linne. Strombus proximus Maury, Bull. Amer. Paleont., V, No. 29, p. 119, PI. 20, figs, 4, 5, 1917. Only incomplete specimens were fonnd, which are identified donbt- fully with this species. Localities.—204, Mona Island (Lobeck). Horizon.—Qiiebradillas limestone, Ponce limestone. Strombus bifrons? Sowerby A single specimen was found among the material collected from the Qiiebradillas limestone near Bayamon by Dr. Lobeck. The in ternal mold shows that the shell is the same shape as 8. hifrons, and measures in height (with tip of spire missing) 32 mm., diameter 19 mm. It is apparently an immature specimen, for the outer li]^ does not flare to any extent, and the anterior notch is not noticeablv recurved. The ornamentation consists of spirals like those of S- hifrons, but with the nodes or spines rather obsolete on the finn: HUBBARD. TERTIARY MOLLUSCA FROM LARES DISTRICT Ho whorl, in which respect it resembles S, gatuiiensis Toula. S, bifrons is characteristic of the Aphera and Sconsia formations in Santo Domingo. Locality,—l^ear Bayamon (Lobeck). Horizon.-—Qnebradillas limestone. Genus Orthaulax Gabb Orthaulax gabbi? Dall Plate XXIIT, Figure 3 A single specimen was obtained from the sea cliff at the month of the Gnajataca River in a stratum of very resistant limestone. The speci- men had been exposed to the polishing action of the weaves, and the original coloring, a light mottled brown, is preserved on the body of the shell near the aperture. The surface of the body whorl ond spire are marked by the numerous faint longitudinal growth lines characteristic of the genus. Viewed from above, the outline is sub- circular, with a slight triangularity as in 0. pvgnax Heilprin and 0. gabbi Dall. The apical angle is about the same as that of 0. gabbi, but considerably more acute than that of 0, aguadillensis Maury, a shell apparently from the same horizon. A marked sub- angularity of the body whorl is very similar to that of 0, gabbi. Above this angulation the wdiorl is strongly convex; below it, the whorl is concave, wdth a slight convexity midway between the angu- larity and the anterior end of the shell. The angularity is strongest at the aperture, on the inner lip, but is obsolete over the final two thirds of the body whorl. A slight shoulder is developed above the angulation on the final portion of the body. Height of shell 65 mui., diameter 38 mm. This shell was examined by Dr. Dall, w^ho states that while the specimen is too poor for positive identification, it is probably 0, gabbi, a shell characteristic of the Chipola horizon. A comparison ndth 0. aguadillensis Maury, a fragmental specimen, show^s that the bell here described is quite a different species. Locality.—204. Horizon.—Qnebradillas limestone. 146 SCIENTIFIC SURVEY OF PORTO RICO Orthaulax portaricoensis, new species Plate XXV, Figures 1, 2, 3, 4, 5 Under this heading are included all the large Strombns-like in- ternal molds, which are among the most abundant forms to be found in the Quebradillas limestone. One of these internal molds was figured by Semmes, in his report on the San Juan District, as Strombus, species indet. The internal molds, taken by themselves, are generically indeterminate, but resemble the molds of a large Strombus. Fortunately, a few of these internal molds were found with portions of the external mold adhering to the specimens, which proves beyond a doubt that these large shells belong to the genus Orthaulax, They attain a size much greater than any species of Orthaulax yet known. The specimens illustrated by figures 1 and 2 were examined by Dr. Dall, who states that: 1 . Figure 1 is undoubtedly an Orthaulax, possibly the same species as Figure 2, but having a more acute or pointed spire. 2. Figure 2 is also an Orthaulax, new species, almost cer- tainly the same species as an undescribed form from Santa Cruz. 3. E'either of these specimens is the same species as the shell described in this report as 0. gabbi? Dall. A large number of specimens, in addition to the two examined by Dr. Dall, show considerable variation in size and elevation, or acute- ness of the spire. The fact that all these variations can be found in shells collected from a single fossiliferous pocket in the limestone, would indicate that they are for the most part variations of a single species, although more than one species of Orthaulax occur in the Quebradillas formation. The apical angle as measured from the external molds, varies from 78° to 90° (largest specimen) ; and from the internal molds, varie- from 60° to 85°. The following are measurements taken from a fe^< of the internal molds: HUBBARD, TERTIARY M0LLU8CA FROM LARES DISTRICT 147 Height Diameter Apical Angle 1 155 mm 105 mm 83° 2 115 80 .. 1.. 85 3 75 82 4 ; 60 75 5 . . . (Fig. 1) . 40 60 6... (Fig. 2) 80 53 73 7 75 50 75 8 70 43 72 9 70 40 71 10 .. 60 35 68 From these measurements, it will be observed that the smaller shells have a higher, more acute spire. This may be a varietal dif- ference. Figures 3 and 4 show the internal mold of one of these smaller shells in which the final whorl has begun to envelop the spire, thus indicating that all of these small shells may be immature individuals. Figure 1 shows the internal mold of the spire, and the external mold of the enveloping dome of an adult shell. The curious openwork structure replacing the shell wall is the cast of the burrow^- ing of a sponge or some other organism. This boring animal seems to have taken a special liking to the thick-shelled Ortliaulax and other ponderous gastropods of the Quebradillas formation. The burrows became infiltrated with lime carbonate, which solidified with the surrounding limestone. The shell structures were then removed by solution, leaving the casts of these burrows in the form of a complex network resembling calcareous algae. Figure 5 shows the dome of an adult shell of the low spired type, and illustrating the degree to which the shell had been riddled with globular chambers, frequently connected by long worm-like passages. Localities,—204, 41, 52(a), 801, and numerous other localities Dot recorded. An excellent specimen was collected by Dr. A. K. l^obeck on the east coast of Vieques Island. Horizon,—Quebradillas limestone, Los Puertos limestone. Char- seteristic of the Quebradillas of the entire north coast of Porto Rico, ^ ^ shown by the collections of Berkey and Semmes. 148 SCIENTIFIC SURVEY OF PORTO RICO Genus Oyprsea Linne Cypraea spurcoides? Gabb Cyprwa spurcoides Gabb, Trans. Amer. Phil. Soc, V, p. 235, 1873. Cyprwa spurcoides Maury, Bull. Amer. Paleont., V, No. 29, p. 115, PL 19, figs. 7, 8, 9, 1917. Apparently the same as the form described from Santo Domingo, except that the crenulations of the two lips are more nearly equal in number. Height 24 mm., maximum diameter 18 mm. Locality,—204. Horizon.—Quebradillas limestone. Cypraea sancti-sebastiani Maury Localities.—%%^^ 232(b), 263?, 233, 235, 237, Juana Diaz. Horizon.—San Sebastian shale, Juana Diaz shale. Genus Cassis Lamarck Cassis, species indet. Plate XXII, Figure 9 Internal molds of a shell which may possibly be a new species. The distinguishing feature is the presence of a strong varix on the body whorl on the side opposite the aperture. Outer lip simple, ap- parently not thickened. The specimens are imiform in size and appear to be adult. The external sculpture, judging from imj)res- sions on the internal molds, consists of from eighteen to twenty broad spirals on the last whorl, with correspondingly fewer spirals on the earlier whorls. Height 30 mm., diameter 23 mm. This shell is apparently of the type of Phalium aldrichi Dall, bnt is not quite as broad as the latter. Localities.—232(b), 236. Horizon.—San Sebastian shale. Genus Dolium Lamarck Subgenus Malea Valenciennes Malea camura Guppy MaleacamuraGui^py, Quart. Jour. Geol. Soc, XXII, p. 287, PL 17, fig. 9, 1866 Malea ringens O&hh (in part). Trans. Amer. Phil. Soc., XV, p. 223, 1873. HUBBARD, TERTIARY M0LLU8GA FROM LARES DISTRICT 149 Malea camura Guppy, Quart. Jour. Geol. Soc, XXXII, p. 525, 1876. Malea camura Dall, Trans. Wagner Inst. Sci., Ill, pt. 6, p. 1584, 1903. Malea camura Maury, Bull. Amer. Paleont., V, No. 29, p. 112, PI. 19, fig. 3, 1917. The specimens average about 3Y mm. by 27 mm. Only internal molds were found with a few fragments of external mold. Locality:—204; and Berkey 98. Horizon.—Quebradillas limestone (abundant). Genus Oolumbella Lamarck Subgenus Strombina Moerch Strombina portaricana, new species Plate XXIII, Figure 4 Protoconch of two whorls, rather large, smooth, naticoid; post-nuclear whorls six to seven, moderately convex; suture distinct, hut not channelled, and becoming obscure on last whorl; surface of whorls smooth except for faint growth striae, and by hump-like varices, or swellings, occurring as early as the third post-nuclear whorl; body whorl with spiral lines, alternating in strength, on the pillar and lower part of whorl, but very faint over the remainder of the whorl, and more closely spaced near the suture and on the pillar. A specimen with eight whorls and base of pillar missing measures in height 19.5 mm., diameter 9 mm. The largest specimen measures in height 33 mm., diameter 17 mm. No complete specimens were found, and none showing the lip or aperture. This shell is apparently related to the group represented by S, lessepsiana Brown & Pilsbry, S, prisma Pilsbry & Johnson, and 8, cyphonotus Pilsbry & «Iohnson. Locality.—204. Horizon.—Quebradillas limestone. Genus Phos Montfort Phos costatus Gabb Plate XXII, Figure 10 Phos costatus Gabb, Trans. Amer. Phil. Soc, XV, p. 212, 1873. Phos costatus Maury, BuU. Amer. Paleont, V, No. 29, p. 88, PI. 14, figs. 13, 14, 1917. The specimens correspond closely to those figured by Maury from ^anto Domingo. Protoconch not preserved in any of the specimens. 150 SCIENTIFIC SURVEY OF PORTO RICO An adult specimen measures in height 29 mm., diameter 14 mm. dumber of whorls eight. Locality.—204. Horizon.'—Quebradillas limestone (abundant). Phos elegans Guppy variety portoricoensis, new variety Plate XXII, Figure 11 SheU small (height about 20 mm.), high spired; whorls rounded, with about fourteen rather sharply rounded ribs, crossed by primary, and fre- quently alternating smaller secondary spirals; small tubercules at inter- sections of spirals and ribs; occasionally two or three longitudinal threads between the ribs which do not cross the spirals; ribs irregularly spaced, especially on the body whorl, where a varix is formed at or near the aperture; ribs on the spire frequently vary in size, but do not form varices. All the specimens are fragmental, but sufficient to show the entire shell except the protoconch. This variety is probably closest to the Santo Domingan occurrence of the species. Locality.—192. Horizon.—Quebradillas limestone. Genius Murex Linne Murex (PhyUonotus) cornurectus Guppy M, iChicoreus) megacerus Gabb, Trans. Amer. Phil. Soc, XV, p. 202, 1873. Not M. megacerus Sowerby. M. cornurectus Guppy, Quart. Jour. Geol.' Soc, XXXII, p. 521, PI. 28, fig. 4, 1876. M. {PUyllonotus) cornurectus Maury, Bull. Amer. Paleont, V, No. 29, p. 103, Pi. 16, figs. 9, 10, 1917. An internal mold^ together with a portion of the external mold was found of a large Murex which seems to be this species. Height (of last three whorls) 80 mm., diameter (of internal mold) 45 mm- Locality,—204. Horizon.—Quebradillas limestone. HUBBATW, TERTIARY M0LLU8CA FROM LARES DISTRICT 151 Genus Alectrion Montfort Alectrion gurabensis Maury variety portoricoensis, new variety variety varicum, new variety Plate XXII, Figures 12, 13, 14, 15 Plate XXIV, Figure 19 The Arecibo limestone contains an abundance of a small shell which is like A. gurahensis Maury, a Santo Domingan form, but which lias some very evident differences from the latter. These shells fall into two distinct varieties, one with coarse ribs, the other with finer, more numerous ribs and a pronounced varix. The former are here called variety portoricoensis, the latter variety varicum. The former is by far the most abundant of the two. Both forms are smaller and have fewer whorls than the Santo Domingo type, but they are not young shells as shown by the uniformity in size among a large number of specimens. ISTo specimen of either variety was found which measures more than 8 mm. in height. The following table shows the relation of the two varieties to the type form from Santo Domingo, as described by Maury (Bull. Amer. Paleont., V, ISTo. 29, p. 91, PL 15, fig. 21, 1917) : Locality.—204. Horizon.—Quebradillas 1 imestone. Genus Fusus Lamarck Pusus henekeni Sowerby Plate XVIII, Figure 5 Fusus henekeri Sowerby, Quart. Jour. Geol. Soc, VI, p. 49, 1849. Fusiis henekeni Gabb, Trans. Amer. Phil. Soc, XV, p. 204, 1873. Fusus henekeni Guppy, Geol. Mag., p. 439, 1874; Quart. Jour. Geol. Soc, XXXII, p. 524, PI. 28, fig. 6 (type), fig. 2 (var. haitensis), 1876. Fusus henekeri DaU, Trans. Wagner Inst. Set., Ill, pt. 6, p. 1584, 1903. Vusus henekeni Grabau, Smithsonian Misc. Coll., XLIV, No. 1417, p. 19, 1904. Fusus henekeni Maury, Bull. Amer. Paleont., V, No. 29, p. 78, PI. 12, fig. 1, 1917. A single specimen was found, with protoconch and body whorl iiissing. Only primary and secondary spirals show on the specimen. 152 SCIENTIFIC SURVEY OF PORTO RICO Table 3 Characters A. gurabensis Maury Santo Domingo A. gurabends var. portoricensis Porto Rico A. gurabensis var. varicum Porto Rico Size Height 11 mm. Diameter 6 mm. Height 7 mm. Diameter 4.5 mm. Height 8 mm. Diameter 4.5 mm. Nuclear whorls 3 smooth 2-2.5 2? Post-nuclear whorls 6 5 5 Character of post - nuclear whorls Convex, angulated and shouldered; ribs narrow, round; wider interspaces. Convex, sub-angular and shouldered. Earher whorls sub- angular—the last two are rounded. Suture Wavy Wavy Slightly wavy Ribs on body whorl 11 12 Slightly oblique 13-14 Oblique Spirals on spire. Penultimate whorl 3 strong, widely sppced 3 weaker above 3 weaker below Penultimate whorl same as in the San- to Domingo shell 3rd post-nuclear 1 weak posterior 3 strong median 2 weak anterior enultimate 3 weak posterior 3 strong median 4 weak anterior Spirals on body 3 or 4 weak posterior 3 strong median 12 weak anterior 2-3 weak posterior 3-4 strong median 10-13 weak anterior 3 weak posterior 3 strong median 12 weak anterior Spirals on pillar 8 6-7, arrangement— 2 strong alternate with 2 weak ? Aperture Round Sub-Round Round Outer lip 8 lirae Thin 15 lirae, alternate long and short Thickened by strong varix Inner lip Posterior denticle Smooth, moderately thick callus. Posterior denticle absent or obscure. Smooth, moderately thick callus. Posterior denticle Anterior canal. . Well defined Broad and deep ? HUBBARD, TERTIARY MOLLVSGA FROM LARES DISTRICT 153 This is probably a small variety, otherwise very close to the type form, but more specimens are required for. a complete description. The spire of eight whorls measures in height 20 mm., maximum diameter 8.5 mm. Locality.—204. Horizon,—Quebradillas limestone. Genus Turbinella Lamarck Turbinella chipolana Dall variety precursor, new variety Plate XXIII, Figures 6, 7 Shell small, fusiform, consisting of three and one-half nuclear whorls and three post-nuclear whorls; protoconch like T. chipolana Dall and T, regina Heilprin, in having a swollen tip, succeeded by smaller nuclear whorls. The tip consists of one and one-half volutions, is transversely ovate, and is peculiar in having a shallow median constriction. The two succeeding nuclear whorls considerably smaller in diameter, the first being gently convex, the last nearly fiat. The latter is succeeded abruptly by sculptured whorls with seven rounded, not nodose ribs, and prominent spirals, of which there are four on the first two, and about twenty-three on the final whorl and pillar. The spirals are separated by wider interspaces. The whorls are marked by a prominent, narrow and wavy sub-sutural band or shoulder, sculptured with at first one and later with two spirals. The interspace immediately below the shoulder is strongly impressed. The spirals are of equal strength, except on the pillar, where faint intercalated threads appear. The entire post-nuclear surface is marked by fine raised longitudinal growth lines, strongest in the interspaces between the spirals. Height of shell 17.5 mm., maximum diameter 7 mm.; height of protoconch 3% mm., diameter of tip of protoconch 2% mm. This shell is probably the ancestor of T. chipolana Dall. It is apparently adult, its small size being indicative of its primitive character. The same is true of variety arecihoense, a mutation from the San Sebastian shell occurring in the Quebradillas lime- stone. All the material available was gone over thoroughly with ^he purpose of trying to find some molds or fragments which would ^how that these shells reach a larger size, but the results were nega- tive. It seems, therefore, safe to assume that the primitive Turhi- neUas were small forms, which did not reach their maximum size 154 SCIENTIFIC SURVEY OF PORTO RICO until the Pliocene. Analogous cases may be seen in some of the genetic groups of Fusus (Grabau, A. W. Phyl. Fusus, Smithson. Miscl. Coll., XLIV, Xo. 1417, 1904). Locality,—84. Horizon,—San Sebastian shale. Turbinella chipolana Dall variety areciboense, new variety Plate XXIII, Figure 8 A single specimen in which the lower half of the body whorl is missing. Protoconch like that of variety precursor, but without median construction of the tip, and with the third whorl almost entirely concealed by the over- lapping of the first post-nuclear whorl, giving the appearance of a two- whorl protoconch. The tip is slightly larger (diameter 3 mm.) than that of precursor, and slightly more swollen when compared with the succeeding whorls. The whorl following the tip is nearly flat, whereas in precursor it is noticeably convex. The first post-nuclear whorl has ribs, spirals, and sub- sutural band, or shoulder, as in precursor and represents the precursor stage. On the next and following whorls, however, the ribs become nodose, and on later whorls there are more spirals than in precursor, with occasionally a fine intercalated spiral. The longitudinal growth lines are similar to those of precursor, but show a tendency to alternate in strength. The sub- sutural band, or shoulder, is prominent in the first two post-nuclear whorls and marked by a single spiral; on the third whorl it is inconspicuous, and marked by two spirals, as in the later whorls of precursor, while on the fourth and fifth (or final) whorls it has disappeared altogether. This fact is interesting in showing the tendency to lose a primitive character which has apparently been completely lost in the Chipolan shell. Height of frag- ment 20 mm., maximum diameter 11 mm. This shell is a mutation from variety precursor^ the precursor, or simple ribbed stage being accelerated and limited to the first post nuclear whorl. The later whorls have nodose ribs and represoiu what may be termed the areciboense stage. This shell is best inter preted as a local mutation not in the direct line leading to T, cliipo lana and T, regina. Locality.—204. Horizon,—Quebradillas limestone. HUBBARD, TERTIARY MOLLUSGA FROM LARES DISTRICT 155 Genus Xancus Bolten Xancus validus Sowerby Turhinellus validus Sowerby, Quart. Jour. Geol. Soc, VI, p. 50, 1849. TurMnella valida Gabb, Trans. Amer. Phil. Soc, XV, p. 218, 1873. TurUnellus validus Guppy, Geol. Mag., p. 438, 1874; Quart. Jour. Geol. Soc, XXXII, p. 523, 1876. TurMnella scolymus Tryon (in part) Man. Conch., IV, p. 70, 1882. Not the recent shell. TurMnella validus Dall, Trans. Wagner Inst. Sci., Ill, pt. 1, p. 99, 1890. TurMnella scolymus Dall (in part). Trans. Wagner Inst. Sci., Ill, pt. 1, p. 97, 1890. Xancus validus Maury, Bull. Amer. Paleont, V, No. 29, p. 83, PI. 13, fig. 5, 1917. Apparently rare. Only a few fragments were found, showing tie sculpture. Locality.—204. Horizon.—Quebradillas limestone. Xancus, new species! Plate XXIII, Figure 9 Known only from fragments. Spire unknown; shell apparently like X. validus Sowerby and X. wilsoni Conrad, but differing chiefly in the greater number of tubercles, or spines, which are along a contracted zone below the rounded shoulder. There are four high, strong columellar folds, the anterior one being smaller than the others. The lower portion of the body whorl is sculptured with strong spirals as in X. validus. The exterior of the remainder of the shell is unknown, except for the presence of the tubercles. Height of body whorl 67 mm., maximum diameter about 50 mm. Locality,—244, 254-5-6. Horizon,—Lares limestone. Genus Mitra Lamarck Mitra henekeni Sowerby Plate XXIV, Figure 1 Ultra henekeri Sowerby, Quart. Jour. Geol. Soc, VI, p. 46, PI. 9, fig. 5, 1849. Mitra henekeni Gabb, Trans. Amer. Phil. Soc, XV., p. 219, 1873. Mitra henekeni Gnppy (in part), Quart. Jour. Geol. Soc, XXXII, p. 528, 1876. Mitra henekeni Maury, Bull. Amer. Paleont., V, No. 29, p. 74, PI. 12, figs. 5, 5a, 1917. 156 SCIENTIFIC SURVEY OF PORTO RICO A single fragmental specimen of a young shell. Protoconch miss- ing. Seven whorls. Height 20 mm., diameter 7 mm. Locality,—204. Horizon,—Quebradillas limestone. Mitra symmetrica Gabb Mitra symmetrica GaJoh, Trans. Amer. Phil. Soc, XV, p. 220, 1873. Mitra symmetrica Maury, Bull. Amer. Paleont., V, No. 29, p. 75, 1917. A single fragmental specimen, consisting of the last two whorls with anterior portion missing. Columellar folds not shown; whorls flattened, slightly convex; suture distinct, but not impressed; aperture elongate-ovate; surface with flattened spirals and much narrower grooves between, which are marked by growth lines. Height 25 mm., diameter 12 mm. It has been suggested that M. symmetrica may be the young of M. titan Gabb. Locality.—280. Horizon.—Lares formation. Genus Olivella Sw^ainson Olivella muticoides Gabb variety portoricoensis, new variety Plate XXIV, Figures 2, 3 The shells vary from high to low spired, and also in the number of columellar plications. They include the types represented by 0. muticoides and 0. muticoides variety canaliculata of Santo Domingo, and there are all gradations between. The sutural canal is extremely broad in all specimens; columellas callus very thick; three to four columellar plications, with several faint ones posterior to these; largest specimen measures in height 12 mm., diameter 4.5 mm. Localities.—204, 671 ; Aguila Point, K 75.2 Ponce-Penuelas road (Mitchell). Horizon.—Quebradillas limestone (extremely abundant) ; and Ponce limestone. HUBBARD, TERTIARY MOLLUSGA FROM LARES DISTRICT 157 Olivella portoricoensis, new species Plate XXIV, Figure 4 Shell small, smooth, moderately high spired; whorls about six; protoconch missing on all specimens; suture distinct, impressed below upper margin of the succeeding whorl, leaving a gap between top of whorl and surface of the preceding whorl; a raised spiral thread appears above the suture, barely showing above the upper margin of the overlapping whorl; columella with two spiral grooves; callus moderately thick; anterior notch shallow, incon- spicuous. Height of shell 12 mm., diameter 5 mm. The distinguishing feature of this shell is the spiral thread at the suture. This thread is not continued on the body whorl. Localities.—204:, 216. Horizon,—Quebradillas limestone. Genus Oancellaria Lamarck Cancellaria laevescens Gnppy Plate XXIV, Figures 5, 6 Cancellaria Iwvescens Guppy, Quart. Jour. Geol. Soc, XXII, p. 289, PI. 17, fig. 12, 1866. Cancellaria Iwvescens Gabb, Trans. Amer. Phil. Soc, XV, p. 239, 1873. Cancellaria Iwvescens Maury, Bull. Amer. Paleont, V, No. 29, p. 64, PL 10, fig. 6, 1917. Cancellaria Iwvescens Ball, Trans. Wagner Inst. Sci., Ill, pt. 1, p. 43, 1890. The specimens are smaller than the Jamaican shells, and show all variations between complete loss of cancellation on the body whorl and merely a diminution of strength of cancellation near the aper- ture. In the latter cases, the spirals continue, but the ribs are ir- regular in occurrence and indistinct or absent for considerable in- tervals. In some shells the ribs on the body whorl become merely irregular crowded growth lines ; callus very thick ; columella with at least three prominent plaits; aperture not widening anteriorly as does that of the Jamaican shell. An average shell measures in height 23 mm., diameter 14 mm. The largest complete specimen measures 26 mm. by 15 mm., while a fragment indicates that the shells attain a size slightly larger than this. Locality.—204. Horizon.—Quebradillas limestone (abundant). 158 SCIENTIFIC SURVEY OF PORTO RICO Genus Tunis Bolten Tunis albida Perry variety haitensis Sowerby Plate XXIV, Figure 7 Pleurotoma haitensis Sowerby, Quart. Jour. Geol. Soc, VI, p. 50, 1849. Turris albida var. haitensis Maury, Bull. Ainer. Paleont., V, No. 29, p. 50, PI. 8, fig. 4, 1917. A few specimens were collected which agree closely with this variety. The largest specimen (spire with body whorl missing) measures in height 22 mm., diameter 8 mm. Locality.—204. Horizon.—Quebradillas limestone. Turris albida Perry variety cf. virgo Lamarck Pleurotoma virgo Lamarck, Anim. s. Vert., VII, p. 94, 1822. Pleurotoma virgo Moore, Quart. Jour. Geol. Soc, IX, p. 130, 1853. Turris (Surcula) virgo Gabb, Trans. Amer. Phil. Soc, XV, pp. 206, 20V, 1873. Turris albida var. virgo Maury, Bull. Amer. Paleont. V, No. 29, p. 50, PI. 8, fig. 6, 1917. A single fragment showing portions of the last two whorls, and indicating a shell of about 60 mm. height. An unusual feature is the absence of secondary spirals. It seems to be an adult form which has retained the form of the young variety virgo. Another special feature is the coarseness of the spirals, the prominent median keel being especially broad and thick, resembling the keels of Ecphora quadricosiata. The suture is indistinct. Interspaces between spirals marked only by the characteristic oblique growth lines. Locality.—204. Horizon.—Quebradillas limestone. Genus Drillia Gray Drillia censors Sowerby variety portoricoensis, new variety Plate XXIV, Figures 8, 9 Shell small, moderately slender; whorls about nine; sutural band as ir the type, but nearly half the axial width of the whorl; sculpture of from HUBBARD. TERTIARY MOLLUSGA FROM LARES DISTRICT 159 four to five prominent spirals, and about 18 sharp ribs which do not cross the sub-sutural band, the latter being smooth, and concave on either side of the spiral ridge which divides the band. The concavity below this spiral ridge is over twice the width of that above the ridge, and much more deeply concave. Height 15 mm., diameter 5 mm. This shell is close to D. consors, but has some distinctive differ- ences. One of the specimens shows the protoconch fairly well. It is rather large, smooth, naticoid, and apparently consists of two whorls. The first post-nnclear whorl is sculptured with ribs only, the spirals being too fine to observe (if present at all) and the sub- sutural band not appearing until the second sculptured whorl. Locality.—204 ; Berkey 98. Horizon.—Quebradillas limestone. Drillia grabaui, new species Plate XXIV, Figure 10 Shell small, slender; decollate specimen (5 whorls) measures in height 14 mm., diameter 4 mm.; protoconch of two smooth, rather large, globular whorls; post-nuclear whorls with sharp, widely spaced ribs and fine, flattened spiral threads, not crossing the ribs and slightly arcuate between the ribs; sub-sutural band like that of D. consors, but narrower and wavy, or fluted, and marked with faint spiral threads and arcuate growth lines indicating a fairly deep, semi-circular posterior sinus. On the penultimate whorl, there are six strong spirals, with three additional ones just below the band, which are fine, crowded, and about the same strength as those on the band. On the body whorl there are twenty-two spirals, and the ribs extend well toward the anterior portion of the shell before dying out. The ribs, spirals, and band appear together immediately foHowing the protoconch stage. This shell has a slight resemblance to D. mao7irisparum Maury, of the Santo Domingan Oligocene, but differs in its slightly larger size, more slender form, different protoconch, and absence of any varix. It probably belongs to the D. consors group. Locality,—204. Horizon.—Quebradillas limestone. Drillia portoricoensis, new species Plate XXIV, FigTires 11, 12 Shell with ten whorls, including protoconch of two smooth, globular volutions; post-nuclear whorls sculptured with low, straight longitudinal ribs and faint spirals, visible only between the ribs, except on the anterior half 160 SCIENTIFIC SURVEY OF PORTO RICO of the body whorl, where they are much stronger, and slightly nodose where they cross the ribs; sub-sutural band of the D. consors type, with dividing spiral ridge prominent in the earlier whorls, but becoming low and incon- spicuous in the adult; band slightly wrinkled where it laps over the ribs of the preceding whorl; lower half of band slightly concave, and smooth except for faint, microscopic spiral lines, and growth lines indicating a broad, sub-angular posterior sinus; adult shells with a strong, thick varix at the outer lip. Height of shell 16 mm., diameter (excluding varix) 5.5 mm. This shell is easily recognizable from its conspicuous varix, and its almost obsolete sculpture. Locality.—204. Horizon,—Quebradillas limestone. DriUia semmesi, new species Plate XXIV, Figure 13 Shell small, broader and lower spired than is usual in members of this genus; whorls seven, including a large protoconch of two smooth, rounded whorls, the first small, the second considerably larger; first post-nuclear whorl sculptured with about thirteen sharp ribs extending from suture to suture, and crossed by three raised spiral ridges, producing a cancellate sculpture; all post-nuclear whorls sharply shouldered, and the ribs, on crossing the shoulder, are strongly arched backward, a feature most noticeable in the later whorls; shoulders of the last four whorls are marked by obscure spirals; later whorls retain the three primary spirals, and on the fourth whorl, smaller intercalated secondary spirals appear. The uppermost primary spiral marks the shoulder angulation. The body whorl has about twelve prominent (or "primary") spirals, with some of the interspaces marked by one or two faint (or "secondary") spirals. All post-nuclear whorls show longitudinal growth lines, arcuate on the shoulder, indicating a wide U-shaped posterior notch. Aperture and anterior portion of shell unknown. Length of most complete specimen, with lower portion of body whorl missing, 8 mm., diameter 4 msxi. This shell is named in honor of Dr. D. R. Semmes, in recognition of his work on the San Juan District of Porto Rico. Locality.—204. Horizon.—Quebradillas limestone. Genus Oythara Schumacher Ojrthara cf . elongata Gabb Mangilia elongata Gabb, Trans. Amer. Phil. Soc, XV, p. 211, 1873; Jour. Acad. Nat Sci. Phila., VIII, p. 351, PI. 46, fig. 34, 1881. HUBBARD, TERTIARY MOLLUSGA FROM LARES DISTRICT 161 Cythara elongata Dall, Trans. Wagner Inst. Sci., Ill, pt. 6, p. 1583, 1903. Cythara elongata Maury, Bull. Amer. Paleont, V, No. 29, p. 59, PL 9, fig. 12, 1917. A single poorly preserved specimen, which seems to be this species or one very closely related. Height 7.5 mm., diameter 3 mm. Locality,—204, Horizon,—Quebradillas limestone. Genus Terebra Adanson Terebra quebradillensis, new species Plate XXIV, Figure 14 Shell small, slender; protoconch of two smooth globular whorls, slightly larger than the succeeding post-nuclear whorl; twelve post-nuclear whorls, rounded as in T. herlinerw Maury; sub-sutural band nearly one-third the axial width of the whorl, marked off by deep, narrow furrow, and faintly striated by one or two spiral threads as in T. wolfgangi Toula; about eighteen arcuate ribs on each whorl, which cross the furrow and sub-sutural band without interruption or change of direction; remainder of whorl below sub-sutural band marked by about nine spiral threads (sixteen on last whorl) which vary in size. A prominent spiral is situated next to the furrow. The rest are finer, and crowded together in groups of two or three. In the earlier whorls they are more uniform in size and distribution; and fewer in number; columella short and non-plicate. The largest specimen measures in height 18 mm., diameter 4 mm. This shell resembles T. berlinerce Maury in its convex whorls and the character of the spiral threads. It differs in its smaller size and wider sub-sutural band. It resembles T. wolfgangi Toula in its bisected or trisected sub-sutural band. Localities.—204, and near Ponce (Mitchell). Horizon,—Quebradillas limestone. Ponce limestone. Genus Conus Linne Conus catenatus Sowerby Plate XXIV, Figure 15 Conus catenatus Sowerby, Quart. Jour. Geol. Soc, VI, p. 45, PI. 9, fig. 2, 1849. Conus interstinctus Guppy, Quart. Jour. Geol. Soc, XXII, p. 288, PI. 16, fig. 3, 1866. Conus catenatus Gabb, Trans. Amer. Phil. Soc., XV, p. 230, 1873. 162 SCIENTIFIC SURVEY OF PORTO RICO Gonus catenatus Guppy, Quart. Jour. Geol. Soc, XXXII, p. 527, 1876. Conus catenatus Maury, Bull. Amer. Paleont., V, No. 29, p. 38, PI. 5, fig. 4; PI. 6, figs. 1, 2, 1917. The specimens vary from concave to only slightly concave spire, from high to moderately low spire, and there is considerable range in size. IJpper whorls carinated ; last five whorls rounded on shoulder and broadly channelled above, with faint arcuate growth lines crossing the channels; posterior third of body whorl smooth; anterior two- thirds marked by spiral threads which alternate with much finer, obscure threads. There are many variations, some of the specimens resembling 0. cercadensis Maury, other resembling (7. hitteredgei Maury, but all evidently variations of (7. catenatus, A typical shell measures in height 31 mm., diameter 17 mm. Locality.—204. Also found by Berkey in the vicinity of Que- bradillas. Horizon,—Quebradillas limestone. Oonus cf. marginatus Sowerby Plate XXIV, Figure 16 Conus marginatus Sowerby, Quart. Jour, Geol. Soc, VI, p. 44, 1849. Conus marginatus Gabb, Trans. Amer. Phil. Soc, XV, p. 230, 1873. Conus marginatus Guppy, Quart. Jour. Geol. Soc, XXXII, p. 528, PI. 29, fig. 5, 1876. Gonus (Chelyconus) marginatus CosQmsinn, Jour, de Conch., T.XI. pp. 44-46, PI. 3, figs. 14, 15, 1913. Conus marginatus Maury, Bull. Amer. Paleont., V, No, 29, p. 46, PI. 7, fig. 11, 1917. A small conus wliicli has features in common with C, marginatus and may be the young of the latter. Whorls eight, including two nuclear; spire moderately high, scarcely concave; whorls carinate except last whorl, which is rounded at the shoulder; whorls of the spire flat above, while the final whorl is slightly channelled above; posterior half of body smooth; anterior half with twelve smooth, flat, spiral bands separated by deep grooves marked by raised longi- tudinal threads, which are limited to the grooves and do not cross the spiral bands. Height 7.5 mm., diameter 4 mm. Locality,—204. Horizon,—Quebradillas limestone. HUBBARD. TERTIARY MOLLVBGA FROM LARES DISTRICT 163 Genus BuUaria Eaflnesque BuUaria paupercula Sowerby Bulla paupercula Sowerhy, Quart. Jour. Geol. Soc, VI, p. 52, 1849. Bulla paupercula Gabb, Trans. Amer. Phil. Soc, XV, p. 246, 1873. Bulla paupercula Qnit^y, Geol. Mag., p. 437, 1874; Quart. Jour. Geol. Soc, XXXII, p. 518, 1876. Bulla paupercula BaMy Trans. Wagner Inst. Sci., Ill, pt. 1, p. 18, 1890. Bulla striata Dall, Trans. Wagner Inst. Sci., Ill, pt. 6, p. 1583, 1903. BuUaria paupercula MsLury, Bull. Amer. Paleont., V, No. 29, p. 18, PI. 3, fig. 8, 1917. The specimens are internal molds, but their general outline seems sufficient to identify them with this species. Fragments of external mold show faint spiral grooves on the anterior part of the shell. Spire depressed. Height 15 mm., diameter 10 mm. Localities,—204:, 664, 235 I Horizon,—Quebradillas limestone, Ponce limestone. Bullaria portoricoensis, new species Plate XXIV, Figure 17 Shell cylindrical, length nearly twice the diameter; spire sunken, imper- forate; aperture longer than shell, extending above the truncate apex; surface with fine, slightly wavy impressed spiral lines, covering all of the shell except the summit, and crossed by slightly curved growth lines. An average specimen measures in height 20 mm., diameter 11.5 mm. The most striking characteristic of this shell is its cylindrical form. The young shell is more globose in form, resembling one of the elongate forms of B, granosa. Locality.—204. Horizon.—Quebradillas limestone. BuUaria granosa Sowerby Plate XXIV, Figure 18 Bulla granosa Sowerhj, Quart. Jour. Geol. Soc, VI, p. 51, PL 10, fig. 10, 1849. Bulla granosa Gabb, Trans. Amer. Phil. Soc, XV, p. 246, 1873. Bulla granosa Gui^py, Geol. Mag., p. 437, 1874; Quart. Jour. Geol. Soc, XXXII, p. 518, 1876. Bullaria granosa Msiury, Bull. Amer. Paleont, V, No. 29, p. 20, PI. 3, fig. 10, 1917. 164 . SCIENTIFIC SURVEY OF PORTO RICO The specimens are slightly more globular than the Santo Domingo shells. There is a great range in size, but the specimens fall into two groups, one of a large size averaging 20 mm. in height and 16.5 mm. in diameter, and the other a small size averaging 14 mm. in height and 11 mm. in diameter. The small shells have a large range in size and proportions, some of the measurements being: Height Diameter 17 mm. 15 mm. 11 mm. 8 mm. 16.5 mm. 12.5 mm. 11.5 mm. 10 mm. The surface sculpture of the shells agrees closely with the shells from the Santo Domingo Oligocene. Localities.—204:, 209% 216, 52(a), 191, 225, 678. San Juan district (Semmes). Culebrinas Point? (Mitchell). Horizons,—Lares limestone to Quebradillas limestone. Ponce lime- stone ? Extremely abundant in the Quebradillas limestone. Plate X Fig. 1. Atrina rahelli n. s. ; nat. size; external mold. Fig. 2. Peden (Pecten) laresense n. s. ; x 1.6 ; left valve. Fig. 3. Pecten (Pecten) laresense n. s. ; x 2 ; right valve. Fig. 4. Pecten (Euvola) reliquus Brown and Pilsbry, var. porto- ricoensis n. var. ; x 2.3. Fig. 5. Pecten (Nodipecten) nodosus Linne; xl.8. Fig. 6. Phacoides (Lucinisca) calhounensis Dall; x2.6; immature shell; gutta-percha cast. Fig. 7. Metis trinitaria Dall ; x 0.76 ; internal mold, left valve. (i Fig. Fig. Fig. Fig. Fig- 1. 2. 3. 4. f). Fig. G. Fig. 7. Fig. 8. Plate XI Pecten (Ohlamys) coUazoensis n. s. ; x 3.5. Pecten (Chlamys) portoricoensis n. s. ; x 2.25 ; right valve. Pecten (Chlamys) portoricoensis n. s. ; x 2 ; left valve. Pecten portoricoensis var. reticulatis ; x 2.25. Pecten portoricoensis var. grandis; x 3.3 ; fragment show- ing prominent ribs. Pecten portoricoensis var. grandis; x 3.3 ; fragment of another shell showing low ribs. Tellina sp. aff. T, (Angulus) atossa Dall; xl.8; gutta- percha cast. Solen (Plectosolen) coUazoensis n. s. ; x 14. PULTE XII Fig. 1. Pecten (Chlamys) grdbaui n. s. ; x 2.25. Fig. 2. Pecten grabaui var. aguadensis; x 2.2. Fig. 3. Pecten grabaui var. hatoensis; x 2. Fig. 4. Pecten grabaui var, guayabensis; x 2 ; ears defective. Fig. 5. Pecten (Chlamys) hodgii n. s. ; x 2.8. Fig. 6, Pecten (Plagioctenium) sebastiends n. 8. ; X lA. Plate XIII Fig. 1. Pecten (Aequipecten) lobecki n. s. ; x 2.5. Figs. 2, 3. Pecten (Plagioctenium) cercadica Maury ; x 1.9. Fig. 4. Ostrea sellceformis Conrad^ variety portoricoensis n. var. ; nat. size; lower valve, adult shell. Figs. 5, 6. Ostrea sellceformis var. portoricoensis; nat. size ; upper valves, exterior and interior; young. Fig. 7. Chione woodwardi Guppy; nat. size; gutta percha cast. Plate XIV Fig. 1. Pecten (Plagioctenium) horinquenense n. s. ; x2.5; right valve. Fig. 2. Pecten horinquenense ; x 2.5 ; left valve. Fig. 3. Avfiusium mauryi n. s. ; x 3.4. Fig. 4. Barbatia cf. honaczyi Gabb; x2.9; gutta-percha cast. Fig. 5. Area dariensis Brown and Pilsbry ; x 2.2. Fig. 6. Area (Scapharca) cf. donacia Dall; x3.7; right valve, gutta-percha cast. Fig. 7. Area cf. donacia; x 4 ; left valve, gutta-percha cast. Plate XV Fig. 1. Osirea anligueuMS Brown; xO.9; lower valve. Fig. 2. Osirea haitensis Sowerby var. ? ; xl.3; interior, young shell. Fig. 3. Osirea haitensis var.?; x 1.3; exterior, young. Figs. 4, 5. Glycimeris coUazoensis n. s. ; x 1.5. Fig. 6. Glycimeris portoricoensis n. s. ; x 1.5 ; gutta-percha cast. Plate XVI Fig. 1. Ostrea cahobasensis Pilsbry and Brown, variety porto- ricana n. var. ; x 0.6 ; valves together; specimen collected by A. K. Lobeck. Fig. 2. Pitaria (Hyphantosomd) carbasea Guppy; x2.2; gutta- percha cast Figs. 3, 4. Tellina {Scissula) grabaui n. s. ; x 2.5 ; gutta-percha casts. Plate XVII Fig. 1. Ostrea cahobasensis Pilsbry and Brown, variety porto- ricana n. var. ; xO.6; lower valve, specimen collected by Lobeck. Figs. 2, 3. Area sp. indet. ; x 2.2. Fig. 4. Godahia (Jagonia) magnoliana Dall, variety borinquenense n. var. ; x 2.5 ; gutta-percha cast. Fig. 5. Chama portoricana n. s. ; xO.8; internal mold with por- tions of external mold of the lamellae at the margin. Fig. 6. Leda peltella Ball x 2.4; gutta-percha cast Plate XVIII Fig. 1. Lucina collazoensis n. s. ; x 0.7 ; left valve, int. mold. Fig. 2. The same specimen,—dorsal view; x 1.1. Fig. 3. Lucina of. chrysostoma (Meusch.) Philippi; nat. size; internal mold. Fig. 4. Phacoides (Miltha) sp. indet. ; x 1.4 ; gutta-percha cast. Fig. 5. Phacoides (Miltha) sp. indet.; x2.6; gutta-percha cast. Fig. 6. Phacoides {Pseudomiltha) laresensis n. s. ; xl.4; internal mold, with portions of the shell preserved near the beak, showing the sculpture. Pl^TE XIX Fig. 1. Oardium muricoides n. s. ; x2.6; gutta-percha cast. Fig. 2. Cardium {Trachycardium) cinderellce Maury, variety altematum n. var. ; x 2.2 ; int. mold- Figs. 3, 4. Cardium cinderellce var. alternatum; x2.6; gutta- percha casts showing variations in the sculpture. Figs. 5, 6. Cardi/um (Trigonocardia) sambaicum Maury, variety portoricoensis n. var. ; x 2 ; gutta-percha casts. Fig. 7. Cardium n. s. ? (aff. (7. sambaicum Maury) ; x 2.5 ; gutta- percha cast. Maury; x 2.5 ; gutta-percha cast. Fig. 8. Cardium (Trigonocardia) haitense var. cercadicum Fig. 9. Cardium haitense variety areciboense n. var.; x2.5; gutta-percha cast. Fig. 10. dementia dariena Conrad; x 1.1 int. mold, specimen from Robles, P. E. Fig. 11. Clementia dariena Conrad; xO.95; int. mold, specimen from CoUazo, P. R., somewhat distorted by pressure. Fig. 12. Clementia dariena Conrad; xO.95; specimen from the Gatun formation, Panama, collected by Prof. J. F. Kemp. Plate XX Fig. 1. Cytherea {Cytherea) berkeyi n. s. ; x 0.75 ; int. moldj speci- men collected by Prof. Berkey. Fig. 2. Same specimen, dorsal view ; x 0.7. Fig. 3. Same specimen; xO.75; gutta-percha cast from fragment of the external mold. Fig. 4. Tellina strophoidea n. s. ; x 2.5 ; right valve, gutta-percha cast. Fig. 5. Tellina strophoidea; x 1.3 ; left valve, gutta-percha cast. Fig. 6. Tellina portoricoensis n. s. ; x 1.5 ; right valve, gutta-percha cast. Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. PlATE XXI Calliostoma portoricoensis n. s. ; x 2.5 ; gutta-percha cast. Turbo fetkii n. s. ; x 2.6 ; gutta-percha cast. Liotia (Arene) coroncUa Dall, variety portoricoensis n. var. ; X 4 ; gutta-percha cast. Neritina (chipolana var. ?) collazoensis n. s. ; x 2. Hipponyx portoricoensis n. s. ; x 2 ; gutta-percha cast. Hipponyx portoricoensis; x 2 ; gutta-percha cast, showing variation with strongly recurved apex. Fig. 7. Crucihulum auricula Gmelin variety portoricoensis n. var. ; x 1.3 ; gutta-percha cast, specimen collected by Prof. Berkey. Fig. 8. Same specimen; x3.3; gutta-percha cast of the internal cup. Fig. 9. Crucihulum auricula? var.; x2.3; gutta-percha cast. Fig. 10. Crucihulum (Dispotcea) collazum n. s. ; x 2 ; interior, showing cup. Fig. 11. Natica (Ampullina?) collazoensis n. s. ; xO.75; decollate shell witii rounded whorls. Fig. 12. Natica collazoensis; x 0.7 ; decollate shell with angulated whorls (int. mold). Figs. 13, 14. Turritella tornata Guppy variety portoricoensis n. var. ; x 1.1 ; int. molds. Fig. 15. Turritella portoricoensis n. s. ; x 2.7 ; gutta-percha cast. Fig. 16. Petaloconchus? collazoensis n. s. ; xl.5. Fig. 17. Pyramidella portoricoensis n. s. ; x 3.6 ; gutta-percha cast. Fig. 18. Bittium sp. indet. ; x 2 ; gutta-percha cast. Plate XXII Epitonium (Oirsotrema) collazoensiQ n. s. ; x 2.2. Same specimen; x 1.5. Turritella mitchelli n. s. ; x 1.4:. Turritella herkeyi n. s. ; xO.85; gutta-percha cast. Oerithium portoricoensis n. s. ; x 3.7 ; gutta-percha cast, showing protoconch. Cerithium portoricoensis; x2.3; gutta-percha cast, show- ing varix on body whorl. Cerithium quehradillensis n. s. ; x2.6; plastolin cast. Same specimen; x2.2; showing aperture and pillar. Cassis sp. indet. ; x 0.8 ; int. mold. Phos costatus Gabb; x 0.8 ; gutta-percha cast. Phos elegans Guppy variety portoricoensis n. var. ; x 1.4 ; gutta-percha cast. Alectrion gurabensis Maury variety portoricoensis n. var. ; X 2.2 ; gutta-percha cast. Alectrion gurabensis var. portoricoensis; x 2.2 ; gutta- percha cast, showing aperture. Figs. 14, 15. Alectrion gurabensis variety varicum n. var. ; x 2.2 ; gutta-percha casts. Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. Fig. 9. Fig. 10. Fig. 11. Fig. 12. Fig. 13. Plate XXIII 2. Cerithium (Campanile) collazum n. s. ; x 1.1. Orthaulax gahhi? Dall; x 0.9. Strombina portoricana n. s. ; x 2.7 ; gutta-percha cast. Fusus henekeni Sowerby; x2.3; gutta-percha cast. Turhinella chipolana Dall variety precursor n. var. ; x 2.5. Same specimen; x 3.7; aperture view. Turhinella chipolana variety areciboense n. var. ; x 2.6 ; gutta-percha cast. Fig. 9. Xancus n. s. ?; nat. size; int. mold of portion of body whorl. Figs, 1, Fig. 3. Fig. 4. Fig. 5. Fig. 6. Fig. 7. Fig. 8. Fig. Fig. 1. 2. Fig. 3. Fig. Fig. 4. 5. Plate XXIV Mitra heneheni Sowerby ; x 2 ; gutta-percha cast. Olivella muticoides Gabb variety portoricoensis n. var. ; xl.75; gutta-percha cast, showing a low spired shell. Olivella muticoides var. portoricoensis; x 1.75 ; gutta- percha cast, showing a high spired shell. Olivella portoricoensis n. s. ; x 3.1; gutta-percha cast. Cancellaria Icevescens Qn^jpji xO.8; gutta-percha cast showing shell with smooth body whorl. Fig. 6. Cancellaria Icevescens; xO.8; gutta-percha cast, showing reappearance of cancellate ornamentation on the final portion of the body whorl. Fig. 7. Turris albida Perry variety haitensis Sowerby; xl.4; gutta-percha cast. Fig. 8. Drillia consors Sowerby variety portoricoensis n. var. ; X 3.5 ; gutta-percha cast. Fig. 9. Drillia consors var. portoricoensis; x 2.3 ; gutta-percha cast Fig. 10. Drillia grahaui n. s. ; x 2.3 ; gutta-percha cast. Fig. 11. Drillia portoricocrisis n. s. ; x 2.3 ; gutta-percha cast show- ing varix. Fig. 12. Drillia portoricoensis; x 2.3 ; gutta-percha cast. Fig. 13. Drillia semmesi n. s. ; x 2.25 ; gutta-percha cast. Fig. 14. Terebra quebradillensis n. s. ; x 18 ; gutta-percha cast. Fig. 15. Oonus catenatus Sowerby; xl.5; gutta-percha cast of specimen collected by Prof. Berkey. Fig. 16. Gonus cf. marginatus Sowerby; x3.6; gutta-percha cast. Fig. 17. Bullaria portoricoensis n. s. ; x 2.2 ; int. mold. Fig. 18. Bvllaria granosa Sowerby; x 2.25; gutta-percha cast. Fig. 19. Alectrion gurabensis Maury variety portoricoensis n. var. ; X 4 ; gutta-percha cast, showing the aperture and pillar Plate XXV Fig. 1. Orihaulax portoricoensis n. s. ; x 0.85 ; internal and ex- ternal mold of the upper half of the shell showing most of the shell wall replaced by casts of a burrows made by a boring sponge or other organism. Fig. 2. Orthaulax portoricoensis; x 0.85 ; internal mold of a large, low spired shell. Fig. 3. Orthaulax portoricoensis; x 0.85; internal mold of a small, high spired shell, probably an immature individual. Fig. 4. Keverse side of the same specimen shown in Fig. 3. Fig. 5. Orthaulax portoricoensis; x 0.85 ; case of the upper portion of a mature shell, made up entirely of the burrow cast? illustrated in Fig. 1. THE UNIVERSITY OF MICHIGAN DATE DUE '/>?"!> 'f*^ f ^ S3 Iff ^ '^1 4 JUL 2 8 199? UNIVERSITY OF MICHIGAN BOUND I SFD241942 3 9015 03458 5623 UNiV. OF r.i(CH. LIBRARY iiiiiililiiBiil^^ iiisiiSiPiiiliSisiiispiiiiliiia^^