ON MOLLUSCA OF THE WEST COAST OF NORTH AMERICA. 545 



180. Arcasemlis is fromW. Africa (not " E.Indies".): one of the many representative 



species between the two West Coasts. 

 185. Noetia reversa, Gray. 

 7.86. Argina brcvifrons, Sby. 

 188. This is the young of Barbati* alternate*. 

 191-195 belong to the"^ group Barbatia. 

 193. =Barbatia Tabogensis, from type. 



203. The young of this shell is Aiicula libella, Rve. Dr. Gould protests against 



some of the interpretations here given to his views. 



204. The W. American pearl-oyster should stand as M. jimbriata, Dkr. It has 



been redescribed as M. barbata, Rve. 



212. Dr. Gould protests against the Pacific shells being regarded as O. Virginica. 

 Mr. Hanley adheres to his original opinion. Fossils sent from the Sand- 

 wich Is. by Mr. Pease (0. Sandwichensis, Pse.) appear scarcely to differ. 



2146. The O. palmula appears a distinct species. 



215. This species is identical with O. no. 384 of C. B. Ad. It may take the name 

 of O, amara from its " bitter flavour." 



224. Sulla AdamsiB. punctulata, C. B. Ad., non A. Ad. 



229. Haminea cymbiformis is closely allied to H. virescens, Sby. 



239. Siphonaria lecanium. S. maura, Sby., is one of the varieties of this species. 

 The S. palmata may prove distinct. S. ferruginea, Rve., is probably de- 

 scribed from the intermediate form. 



242. lanthina striulata. Name given in ignorance of striolata, Ad. and Rve. j and 

 not needed, teste Rve. 



245. The Denialium hyalinum of Phil, is probably the young of D. semipolitum : 

 this species is distinct. 



247. The Dent, pretiosum of Nutt. is a northern species j this is most likely D. lac- 

 teum, Phil. 



248-250. This typical group of Chitonids retains the Linnean name in Dr. Gray's 

 arrangement ; and as he first pointed out the generic distinctions in the 

 family, his judgment is to be preferred. 



252-254, 256. These species belong to Ischnochiton, Gray. 



255. Lepidopleurus, Risso, has sculptured valves and scaly margin, and is probably 

 synonymous with Lophyms, H. and A. Ad. The name may be retained for 

 the "' Lophyroid " Ischnochiton here described, the peculiarities of which have 

 been confirmed by adult specimens in Mus. Cuming, and by other species. 



257. Chiton, H. and A. A(L,=:Acanthoplettra (Guild.), Gray. 



262. = Nacella pcltoides, n. s. (described from Cape St. Lucas specimens). 



263. The true Lottia pintadina of Gld. (teste figured types) consists entirely of 



varieties of A. patina. 



265. The " large flat shell " referred-to is Tecturella grandis, Gray, Brit. Assoc. Rep. 

 1861, p. 137. Tecturella is preoccupied by Stimps. Gr. Manan Invert. It 

 being needful to divide the old genus Acmaa, Lottia may be used for this 

 section. By reviving synonyms as sectional names, when a genus is divided, 

 good names may be retained in a restricted sense, and the burden of a spu- 

 rious nomenclature lessened. The species is Lottia gigantea (Sby. Gen. j. 



269. Scutellina navicelloides, Cpr.,= Crepidula osculans, C. B. Ad. 



280. This should stand as Gadinia stellata, Sby., that name having been given to 

 the normal form, Rep. pi. 7. f. 3a, of which pentegoniostoma, f. 3/\| is only 

 an accidental variety. 



282. Callopoma Fokkesii=;tessellatum, Rve., is the Lower Californian form, and 

 probably distinct. 



28-1&. = Turbo phasianella, C. B. Ad., non Melaraphe phasianella, Phil. 



289. The first name is T. eximius, Rve., P. Z. S. 1842, p. 185 ; Mke.'s shell bearing 

 date 1850. It appears identical with " Javanicus, Lam.," in Mus. Cum., and 

 is extremely like " speciosus, Japan." Trochus being now generally retained 

 for the Niloticus group, which contains the largest forms, it is best to revive 

 Swainson's excellent name Calliostoma for the " Ziziphinus "group. A specific 

 name should not be used for a genus, where a distinctive name has already 

 been accurately described, 

 1863. 



