132 GEOLOGY AND PALEONTOLOGY OF THE WEST INDIES. 



Pecten (Chlamys) anguillensis Guppy. 

 (Plate 10, Figures 1 a, b, 2.) 



Pecten anguillensis Guppy, Proc. Sci. Asso. Trinidad, p. 175, 1867. 

 Pecten anguillensis Guppy, Geol. Mag., Dec. 2, vol. 1, p. 446, plate 18, fig. 24, 1874. 

 Pecten (Chlamys) anguillensis Dall, Trans. Wagner Inst., vol. 3, pt. 4, p. 715, 1898. 

 Pecten (Chlamys) anguillensis Brown, Proc. Acad. Nat. Sci. Phila., p. 602, 1913. 



The following is Guppy's original description of this species, Decem- 

 ber 1867: 



"Shell fan-shaped, ornamented with radiate muricate striae, and about 10 

 or 11 prominent rounded ribs, which are crossed by concentric striae, the con- 

 cave interstices broader than the ribs. Upper valve nearly flat, lower one 

 gently concave. 



"Miocene, Anguilla. Allied to P. peedeensis Tuomey and Holmes, North 

 America." 



The following diagnosis was made from one of Guppy's specimens 

 which agrees perfectly in size and shape with the published figure of 

 P. anguillensis and is probably the type specimen. If such is the case 

 the figure is very bad. The Guppy collection contains two other 

 specimens, one an internal cast which shows that the shell is grooved 

 internally in accordance with the external ribbing. A fourth specimen 

 in the same lot belongs to a different species (Pecten perplexus). 



Shell oblique; right valve the more convex, with 12 or 13 ribs, left valve 

 flatter with 11 ribs; ribs high, round, with equal or slightly wider interspaces; 

 ribs and interspaces covered with radiating threads; submargins narrow, 

 steep, apparently smooth; ears small, unequal, with radiating riblets, anterior 

 the larger. 



Alt., 32.8 mm.; lat., 30 mm.; diam., 11 mm. 



Pecten anguillensis appears to be much more abundant in Antigua 

 than in Anguilla. The Antiguan specimens have as many as 15 ribs 

 and are somewhat variable in convexity and in the shape and elevation 

 of the ribs. The ribs are broader and not so high as in the specimens 

 from Anguilla, and the radiating threads are wider spaced and more 

 elevated ; the latter character may be due to the better state of preser- 

 vation of the Antiguan specimens. 



Localities. Anguilla, Guppy; Crocus Bay, Anguilla; Hodge's Bluff, 

 Willoughby Bay, and Friar's Hill, Antigua, Vaughan, stations 6893, 

 6862, 6881, 6856. Professor Brown records the species also from 

 Wetherell's Bay, Antigua. 



Geologic horizon. Oligocene. 



Type. Probably the specimen figured in this paper (figs. 1 a, 6). 



Figured specimens. U. S. Nat. Mus. Nos. 115532 (type), 167097. 



Pecten clevei, new species. 

 (Plate 10, Figures 3, 4.) 



The following is a description of this species: 



Left valve gently convex, with about 21 small concave ribs, somewhat 

 variable in size, with nearly equal interspaces; concentric sculpture of minute 



