225 



fttsca ; septo subdiaphano, margine mayis declivi ; intua et ad 

 apicem atro-purpureo ; margine acuto. ^,,^ 



Long. 1-97, lat. 1-26, alt. -54. 



Hab. California Superior ; legit T. Nuttall. Museis suo, Jay, 

 Cuming. 



This shell is regarded by Dr. Jay as identical with Cr. onyx, Sow. 

 {^=Cr. hepatica, C.B. Ad.? non Desh.), which it resembles in the 

 character of the spire, aud in the general appearance. The specimens 

 examined differ in colour, which is not so lustrous ; iu habit of 

 growth, which is not lamellar ; in the sepium, which is rather less 

 opaque, particularly in the young shell ; and especially in the epi- 

 dermis, which is glossy, and only interrupted by the wrinkles of 

 growth beneath. Whether these differences are of specific value, 

 mušt await the examination of more nuraerous specimens. Vide 

 B.M. Maz. Cat. no. 340, p. 278. 



- 96. Crepidula , sp. ind. 



Crepidula navicelloides, Nutt. MS. in Jay's Cat. no. 3035. 



Comp. Crepidula minuta, Mid. Mal. Ross. pi. U. f. 6, 7. p. 101 

 (Sitka). 



Comp. Crepidula nummaria, Gould, Exp. S helis, p. 15. 



Hab. California. Mus. Jay, Nutt. 



From the very imperfect materials, it is impossible to determine 

 this species with confidence. It has a great resemblance to C. nivea, 

 Tar. squama (v. B.M. Maz. Cat. no. 341. p. 280), but the apex appears 

 distinct both from that and C. unguiformis. Middendorffs young 

 shell is probably eonspecific ; and the species may hereafter include 

 the following. 



97. Crepidula explanata, Gould, Mex. & Cal. Shells, p. 4. 

 pi. 14. f. 7 ; P. Z. S. 1856, p. 205. 



= Crepidulu exuviata, Nutt. MS. in Jay's Cat. no. 3027. 



= Crepidula perforans, Vai. Voy. Ven. 



Hab. California. Mus. Jay, Gould, Cuming. 



This shell appears an aberrant form of the lašt species, caused by 

 living in the hole of a Lithophagus. The young shell is normai ; 

 the nucleus is large, smooth, not imbedded as in Cr. unguiformis^ 

 nor stflnding out as in Cr. nivea. There is only one large spirai 

 turn. The most peculiar character of the shell is the cancellation 

 between the laminse, but this only appears in some of the specimens. 

 Distortions occur of the true Cr. nivea, almost equally aberraut in 

 form. Vide B.M. Maz. Cat. p. 284. 



- — 98. Crepidula aculeata, rar. 



= Crepidula Californica, Nutt. MS. B.M. Maz. Cat. p. 268. 

 no. 334. 



Hab, Sta. Barbara, freąuens. Mus. Nutt., Brit., Warrington, &c. 



99. Crucibulum spinosum, Sow. B.M. Cat. Maz. Moli. 

 no. 344. p. 290. 



Hab. Monterey, rarissime. Mus. Nuttall. 

 No. CCCXV. — Proceedings of the Zoological Society. 



