132 COCCULINA. 



C. rathbuni Dall. PL 25, figs. 5, 6. 



Shell white, depressed, the slopes flattened, sides subparallel, 

 with slight radiating and concentric sculpture and a subcentral apex 

 from which the nucleus is usually lost, leaving a little scar on the 

 shell. Length 10-13 mill. 



Shell depressed, white, thin, with sides nearly parallel and their 

 slopes lightly flattened, and with ends similarly broadly rounded ; 

 sculpture of faint closely (but irregularly) set grooves radiating 

 from a smooth apex (which has originally a subspiral nucleus), and 

 crossed by concentric growth lines, which are more or less ir- 

 regular in different individuals ; faint yellowish areas seem to in- 

 dicate a thin, very closely adherent epidermis ; apex prominent, 

 more or less incurved and slightly laterally compressed, usually 

 showing a scar where the embryonic nucleus was attached ; inside 

 polished or smooth. (Dall.) 



Length 11, breadth Q-5, height 275 mill. 



Another dead specimen is three times larger. 



100 miles S. and E. from Martha's Vineyard in 506 fms. ; Off 

 Barbados in 399 fms. ; off St. Vincent in 464 fms. ; off Martinique in 

 502* fms. 



C. Rathbuni Dall, Proc. U. S. Nat. Mus. 1881, p. 402 (1882) ; 

 Blake Gastrop., 347, t. 25, f. 5, 7, 7a. — Verrill, Trans. Conn. Acad. 

 v, p. 534. 



C. beanii Dall. PI. 25, figs. 23, 24. 



Shell elevated, white, the anterior slope much the longer and con- 

 spicuously arched, the posterior slope excavated concavely, the 

 apex elevated, subposterior and much incurved, the nucleus gener- 

 ally gone in adults, leaving a little scar ; sculpture stronger and 

 more distinctly cancellated in some specimens than in C. Rathbuni. 

 The young are more sharply sculptured than the old, and at the 

 intersections the riblets are nodulous or even slightly spinose, the 

 shell is smaller than in C. Rathbuni. (Dall.) 



Length 8, breadth 5, height 4 mill. 



79 miles S. of i) fartha's Vineyard, in 100 fms.; also in the West 

 Indies off Barbados, Martinique, Guadelupe and St. Vincent, in 399 

 to 583 fms. 



C. Beanii Dall, Proc. U. S. Nat Mus. 1881, p. 403 (April, 1882) ; 

 Blake Gastrop., p. 347, t. 25, f. 2, 4, 8.— Verrill, Trans. Conn. 

 Acad, v, p. 533. 



