DR. P. P. CARPENTER ON THE SHELLS OF PANAMA. 23 



sonic "i-f undoubtedly C. nivea ; others truly C. unguiformis ; and 

 others probably C. nivea, but with the riblets worn away by the 

 crabs. 



351. Crepidula nivea, M. 341. The specimens are small and 

 poor ; mostly rough, of the variety striolata passing into lessonii. 

 Wherever the apex is perfect, it presents the characteristic riblets, 

 but is generally white, not brown as in most of the finely grown 

 Mazatlan shells. 



S52. Crepidula oseulans. This is a perfect and extremely beau- 

 tiful specimen of Scutellina navicelloiiies, M. 269. The Professor 

 did not observe the non-spiral patelloid apex, and regarded the 

 " uavicelloid " columella as an extremely narrow deck. To the diag- 

 nosis in the Maz. Cat. may now be added " apice obtuso, siiblaioi ; 

 vertice haud spirali, vix conspicuo." 



353. Crepidula rostrata^=C. ridunca, M. 338, ?non Sby. The 

 examination of a large series of specimens from the temperate fauna 

 has led me unexpectedly to confirm Mr. Reeve's opinioQ that they 

 are distinct. The northern shell is C. adunca, Sby. {^Qarnotia 

 [Gray] solida, Hds.= C. rostriformis, Gld.) ; and the tropical shell 

 must take the prior name, C. uncata, Mke. (= C. rostrata, G. B. Ad., 

 Rve. = C. adunca, Maz. Cat., non Sby.). 



354. Fissurella (equalise Fissurellidcea ce. 



355. Fissurella alta = Glyphis alta, M. 280. 



356. Fissurella macrotrema. Stet. 



357. Fissurella microtrema. These are dead specimens, of which 

 some are F. rugosa, var., M. 273. 



35S. Fissurella mus^^-Glyphis inaqualis, var., M. 279. These 

 shells are intermediate between the typical form and pica. 



359, 360. Stent. 



361. Fissurella vireseens. It is doubtful whether any of the spe- 

 cimens are of the true vireseens, M. 271, as they run into nigro- 

 punctata by insensible gradations. Perhaps both species may pro\ e 

 identical. 



362. Siphonaria characteristica=^S. gigas, var. 



363. 364, 365. Stent. 



366. Siphonaria 1. pica. These are young dead limpets (not 

 SiphonaritB). 



3G7. Lottia 1 patina, C. B. Ad. (non Esch.). These shells differ 

 from Acmcea mesoleuca, M. 263, in being black instead of green, and 

 are prettily striped. 



368, 369, 370. Lottia, sp. ind. There may be two or even more 

 species of Acmsea, but it is not impossible that there is only one 

 among the professor's Lottise, some of the specimens being the 

 young of ? Patella, no. 371. -. q» 



