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



preservation of types therefore, and the interchange of specimens 

 named from types, is of the first importance to save tlie time and 

 ensure the accuracy of succeeding writers. The Smithsonian Insti- 

 tuiion has fully recognized this principle by directing that the first 

 available duplicate of all type species described from its collections 

 shall be deposited in some museum open to students on the other 

 side of the Atlantic. 



As the authorities of Amherst College had not taken any steps 

 to figure their iinitpie specimens, and as Prof. Adams's determina- 

 t'.ons of old species had not been verified, I made it my business 

 (^when visiting America to deposit the first duplicate series of the 

 Mszatlan Shells in the New York State Museum at Albany) to com- 

 pare Prof. Adams's collection, on the spot, with his published book, 

 in my copy of which I made my notes and sketches at the time. 

 Every facility was afforded me by the Curator. I was allowed freely 

 to handle the specimens in the presence of his assistant, and to draw 

 the minute species under my microscope. I took with me for com- 

 parison the drawings of the minute Mazatlan sliells in the British 

 Museum. The species being numbered in both the Panama and the 

 Mazatlan lists, it is easy now to institute a comparison between them. 

 They are here distinguished by the initials P. and M. 



P. 1. Ovula avena. May be distinct from Radius variabilis, 

 IVI.,435, being much more stumpy, with a thicker lip ; but the few 

 S])ecimens are in poor condition, and the difterences may be accidents 

 of station. 



2. Ovula emarginata^Carinea e. Quite distinct from its Carib- 

 bean analogue C. gibbosa. 



3. Ovula neglecta, C. B. Ad., is probably a small variety of Ra- 

 dius variabilis. 



4. Ovula variabilis, C. B. Ad. = Radius v., M. 435. 



5. Ovula, sp. ind., probably = t-a/v'aS///*, jun. 



6. Cj/prcea arabicula= Aricia a., M. 438. 



7. Cyprcea cervinetta^=C. exanthema, M. 436. Having now 

 examined a multitude of specimens from ditferent stations on the 

 •west coast, which differ from each other quite as much as they do 

 from the typical Caribbean forms, I am confirmed in the belief of 

 their identity. 



8. Cyprcea 2ninctulaf.a= Aricia p. Erroneously given, in i\I. 

 p. 3/4, as a probable synonym of A. arabicula. It is less thickened 

 at the sides, with smaller spots, xllthough specimens of arabicula 

 graduate into it at the back, it may always be known by the moutli, 

 which has its teeth much further apart. 



9. Cyprcea pustuluta=Trivia p., M. 439. 



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