MUSEUM OF COMPARATIVE ZOOLOGY. 251 



Conrad's name as it has been traditionally applied. I find the next name in 

 order, to be Leda cuneata of Sowerby, which from specimens identified by 

 Hanley (and coming from Catalina Island, California) is quite evidently the 

 same as L. jamaicensis D'Orbigny. The latter author described and figured a 

 young specimen, so that the magnified figure he gives agrees only with speci- 

 mens of the same age; but, for them, it is very exact. I have examined a 

 large number of L. commutata Phil., and, while it is very similar, I cannot 

 convince myself that it is the same. The commutata generally has one very 

 strong anterior rib, and the acuta has a shallow groove bordered by two faint 

 ribs. This is the most obvious character, though there are others. The L. unca 

 of Gould was not figured and the description is brief. It is described as hav- 

 ing the dorsal area keeled and smooth, characters not appropriate to any of 

 the just mentioned forms, though shared by the proportionally more elongate 

 L. Bushiana Verrill, which is not " acutely rostrate." The vitrca, acuta, 

 and second unca of Verrill all have the dorsal area strongly sculptured, even 

 when worn; more so, generally, than the rest of the shell. None of these 

 therefore should be identified with unca Gld. Verrill's second unca (1. c.,p. 260), 

 which seems distinct from either vitrca or acuta, may take the name of Ver- 

 rilliana. The variety cerata is united with the typical vitrea by intermediate 

 forms. 



Leda acuta Conrad. 



Nucula acuta Conrad, Am. Mar. Conch., p. 32, pi. vi. fig. 3, 1831. 

 Leda jamaicensis D'Orbigny (1846), Dall, Bull. M. C. Z., IX. p. 124, 1881. 

 Leda cuneata Sowerby, P. Z. S., 1832, p. 198. 

 Leda inornata A. Adams, fide Hanley, from type. 



Leda unca Verrill, Trans. Conn. Acad., V. p. 572, 1882, pi. Iviii. fig. 41 (not VI. 

 p. 260.) 



Plate VII. Figs. 3 a. 3 b, 8. 



Habitat. Sand Key, 80 fras. ; off Sombrero, 54 and 72 fms. ; Jamaica, Santo 

 Domingo (D'Orb.); off southern New England, 85-165 fms. (Verrill). Florida 

 (Hemphill). 



The relations of this species to the others have been considered under the 

 preceding species. I have not been able to consult Conrad's original publica- 

 tion, but Binney (Bibl. N. Am. Conch.), citing from it, refers the species to Say. 

 In other places Conrad puts his own name after it. 



The specimens from Yucatan Strait cited in the preliminary report under 

 this species, on further study, appear to be L. messanensis Seg. L. commutata 

 Phil., as before mentioned, appears to be diff"erent from this, though a closely 

 allied form. The frayilis of Cliemnitz, a badly figured and described shell, to 

 which Dr. Jefi'reys would refer L. commutata, is much larger than any known 

 commxdata, and is referred by Hanley to a Chinese species. Doubtless Chem- 

 nitz would have included commutata in his species. The Lembulus deltoideus 



