DR. P. P. CARPENTER ON THE SHELLS OF PANAMA. 17 



coordinate with considerable attrition, and an 'umbilicus tilled with 

 dirt. It appeared to me regularly rounded, without any keel. The 

 " few spiral striae " are probably the remains of what once covered 

 the whole surface. 



263. Vitrinella panamensis=M. 295. 



264. Vitrinella parva=M. 296. 



265. Vitrinella perparva=.M. 304. The coronation of the upper 

 keel is seen (though not described) in the type specimen. 



266. Vitrinella regularis. The unique shell can hardly be called 

 " subdiscoidal," since the " spire is convex, moderately elevated." 

 I could not find the "impressed spiral line." It belongs to Ethalia. 



267. Vitrinella seminuda. The unique type of this species also 

 is much worn. I could not discover the " minute striae of growth." 

 Beneath, there are five spiral lirae, and a few spiral striae near the 

 mouth. The umbilical region and the base have fine radiating distant 

 striae. It comes nearest to V. carinulata, M. 309, but is distinct. 



268. Vitrinella tricarinata. This unique type is also worn. 

 The spiral keels are scarcely " prominent," that on the periphery 

 being decidedly faint. The "transverse striae" are between the 

 suture and the nearest rib. The umbilical striae are very faint. 



269. Vitrinella valvatoides. This species probably belongs to 

 Ethalia. Beside the keels, there are three obsolete spiral lirae two 

 on the base, and one above the periphery. The umbilicus is bounded 

 by a long, thin callosity, which gives a character to the shell inter- 

 mediate between the two genera. 



270. Solarium, sp. ind. a. Of the form represented by this 

 species and the next I have been able to examine a large number of 

 specimens collected at Cape St. Lucas by Mr. Xantus, and in the 

 Gulf of Mexico. I know of no mark by which to distinguish the 

 shells from the two oceans. From each locality they vary greatly 

 in the size of the umbilicus, and in the strength of sculpture, number 

 of knobs, &c. I should consider them all as varieties of S. granu- 

 latum, Lam. S. quadriceps, lids., appears distinct, though it may 

 only be an extreme variety. 



271. Solarium, sp. ind. b. This contains the specimens with 

 coarser sculpture than the last. 



272. Solarium, sp. ind. c. This is a distinct species of Torinia y 

 having the size and general aspect of Helix rotundata. 



273. Trochus catenulatus= Modulus c., M. 401; 



274. Trochus coronulatus=0mphalius c. This species reappears 

 at Cape St. Lucas, and is closely allied to O. ligulatus, M. 293. 



275. Trochus leanus=Calliostoma I. This distinctive generic 

 name is strongly to be preferred to the specific Ziziphinus. 



276. Trochus lima. This shell exactly accords with Calliostoma 

 anlonii, Koch, in Mus. Cuming. 



191 



