268 MAZATLAN UNIVALVES 



are often by no means constant. It has been the object, in 

 the following selection from the multitudes of individuals in the 

 Mazatlan collection, to illustrate the variations of which each 

 species is susceptible.* 



334. CEEPIDULA ACULEATA, Gmel. 



PateUa aculeata, Gmel. p. 3693. Dillw. Descr. Cat. p. 1020, 



no. 11. 

 Patella fornicata aculeata, Chemn. Conch. Cab. vol. x., p. 334, 



pi. 168, f. 1624-5. 



Patella fornicata, var. Sclireib. Conch, vol. i. p. 338. 

 La Retorte epineuse, Favanne, vol. i. p. 564, pi. 4, f. F. 2. 

 Crepidula aculeata, Lam. An. s. Vert. vol. vii. p. 642, no. 3. 



Desh. Fnc. Meth. Vers, vol. ii. p. 27, no. 11. Sow. Gen. 



f. ^B. M. Cat. Cuba Moll. p. 33, no. 395. .S. M. Cat. 



D'Orb. Moll. p. 48, no. 415. WBrod. in Proc. Zool. Soc. 



1834, p. 39 Gould, ms. Cat. Cal. Shells Dkr. Ind. Moll. 



Guin. no. 94. Krauss Sudafr. Moll. p. 69, no. 4. 

 Crepipatelia aculeata, H. $ A. Ad. Gen. i. 369. 

 + Crepidula Capensis, B.M.\ (?=Quoy fy Gaim. Voy. Astr. 



vol. iii. p. 424, pi. 72, f. 13, 14 ; Lam. An. s. Vert. vol. vii. 



p. 645, no. 9 -.Krauss, Sudafr. Moll. p. 68, no. 1.) 

 + Calyptrsea (Crepipatelia) echinus, Brod. in Proc. Zool. Soc. 



1834 p. 39 Trans. Zool Soc. vol. i. p. 203, pi. 27, f. I Mull. 



Syn. Nov. Test. Viv. p. 148. H. $ A. Ad. Gen. i. p. 369. 



(Crepidula e.) Lam. An. s. Vert. vol. vii. p. 650, no. 23. 



C. B. Ad. Pan. Shells, p. 226, no. 344. 

 + Calyptraea (Crepipatelia) hystrix, Brod. Proc. Zool. Soc. 



1834, p. 39 -.Trans. Zool. Soc. vol. i. p. 203, pi. 29, f. 2. 



H. fy A. Ad. Gen. i. p. 369. (Crepidula h.) Lam. An. s. Vert. 



vol. vii. p. 650, no. 22. 

 + Crepidula cosi^ta, Mke. in Zeit.f. Mal.l84!7, p. 183, no. 32 : 



(non Sow. nee Quoy, nee Desh. in Lam. An. s. Vert. vol. vii. 



p. 644, no. 7.) Id. 1851, p. 35, no. 122. 

 + Crepidula Californica, Nuit. ms. in Warrington Mus. 



* I have been compelled to unite several species usually regarded as very dis- 

 tinct. On shewing a series to an author deservedly distinguished, proving that 

 four species were identical which he had grouped under two subgenera, he com- 

 plained that I had kept all the puzzling shells ! It is easy, as one naturalist is 

 recorded to have done, to smash all specimens not according with our classifica- 

 tion; or as another, to pick out all the leading forms and describe them as 

 distinct species, genera, or even orders, disregarding the intermediate ones which 

 would have proved them identical ; but the interests of science are not served by 

 either one course or the other. Our object must ever be, not to make Nature 

 aweak our language, but to find out what is the language of Nature. 



