268 MAZATLAN UKIVALVE8 



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

 the following eeleetion from the multitudes of individuals in the 

 Mazatlan collection, to illustrate the variations of which each 

 species is susceptible.* 



334. Ceepidula aculeata, Chnel. 



Patella aculeata, Gmel. p. ZQ^Z.—Dillic. Dcac,'. Cat. p. 1020, 



no. 11. 

 Patella fornicata acxileata, Chemn. Conch. Cah. vol. i., p. 334, 



pi. 168, f. 1621-5. 

 Patella fornicata, var. Schreih. Coiich. vol. i. i). 338. 

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

 CrepidiJa aculeata. Lam. An. s. Vert. vol. via. p. 642, no. 3. — 



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



f. 4.-5. M. Cat. Cuba Moll. p. 33, no. 395.-5. M. Cat. 



D'Orb. Moll. p. 48, no. ilo.— ?? Brod. bx Froc. Zool. Soc. 



1834, p. 39— Gould, ms. Cat. Cal. Shells.— Dh\ Ind. Moll. 



GvAn. no. 94. — Kraus.s Sudafr. Moll. p. 69, no. 4. 

 Crepipatella aculeata, H. S)" A. Ad. Gen. i. 369. 

 + Crepidula Capensis, B. M. : {?=Q,uoy Sf 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.) 

 + Calyptrpca (Crepipatella) echinus, Brod. in Froc. Zool. Soc. 



1834 p. Sd.—D-ans. Zool. Soc. vol. i. p. 203, pi. 27, f. l.—Miill. 



Syn. Nov. Test. Viv. p. 148.— jff". ,f A. Ad. Gen. i. p. 369.— 



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



C. B. Ad. Fan. Shells, p. 226, no. 3-44. 

 + Calyptra?a (Crepipatella) hvstrix, Brod. Froc. Zool. Soc. 



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



H. Sf A. Ad. Gen. i. p. 369.— (CrepidiUa h.) Lam. An. s. Vert, 



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

 -(-Crepidula costata, Mke. in Zeit.f. Mai. 1847, p. 183, no. 32: 



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



p. 641, no. 7.)— Id. 1^51, p. 35, no. 122. 

 + Crepidula Californica, JVuft. ms. in Warrington jMus. 



* I have been compelled to unite seTeral species usually regarded as Tery dis- 

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

 lour 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 

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



