n DR. P. P. CARPENTER ON THE SHELLS OF PANAMA. 



203. Cerithium pauperculum is a good, new species of Chrysallida. 

 The Professor probably did not recognize the Chemnitzoid apex and 

 the Odostomoid plait. The following alterations may be made in 

 the diagnosis: Shell pale orange [not horn], with six [not five] 

 keels on the spire ; spiral ridges anteriorly fainter [not obsolete] ; 

 apex sinistral [not acute], of three Paludinoid whorls, the last large 

 in proportion; columella effuse [not canaliculated], with a long, 

 slender, slanting plait. 



204. Cerithium pulchrum=Cerithidea p. A distinct and truly 

 beautiful species, seldom obtained by collectors. 



205. Cerithium reevianum=Cerithidea montaynei, M. 394. 



206. Cerithium validum Cerithidea varicosa, M. 395. The 

 Southern shells, in all their changes, present such a different aspect 

 from the Gulf specimens, that I am inclined to regard the form Ma- 

 zatlanica as distinct, of which C. albonodosa may prove a variety. 



207. Triphoris alternate, M. 391. 



208. Triphoris inconspicuus is scarcely even a variety of the last ; 

 and does not differ so much as the specimens described under the 

 same name, M. 392. 



209. Triphoris infrequens is not the shell described, under the 

 same name, M. 393, but is the Cerithiopsis tuberculoides, M. 557. 

 It would have been strange if I had recognized the shell from the 

 diagnosis ; for both of the specimens are dextral. The apex is nearly 

 smooth. I forbear to redescribe nos. 392, 393 of the Maz. Cat., 

 as they were separated principally in deference to Prof. Adams's 

 authority, until more numerous specimens should have been examined. 



210. Turritella banksii=T. goniostoma, jun., M. 379. 



211. CfBcum dimi7iutum = Caecum firmatum, jun., with numerous 

 close rings. All the Professor's specimens of this genus were dead ; 

 most of them pierced by Proboscidifers. They fully confirmed the 

 judgments I ventured to form of them in the Maz. Cat. and in the 

 " Monograph of the Csecidse," P. Z. S. 1858, p. 413 et seq. 



212. Caecum eburneum C. firmatum. The rings vary from 

 twenty-six to thirty-three. 



213. Caecum firmatum, M. 368. Add to the diagnosis in Maz. 

 Cat. p. 320, last line, '* operculo mx concavo, suturis minus definitis." 



214. Caecum lave. The two specimens are too worn for identifi- 

 cation, but will pass sufficiently for the species described under the 

 same name, M. 372. 



215. Caecum laqueatum. A good species of the Elephantulum 

 group: v. Maz. Cat. p. 315, and P. Z. S. loc. cit. p. 420. 



216. Caecum monstrosum = C. firmatum in the adolescent stage. 



217. Caecum parvum turns out, as was expected, to be = C. unda- 

 turn, M. 371. The unique specimen is stunted and dead. 



218. Caecum pygmceum is a small but nearly adult C. firmatum. 



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