ON MOLLUSCA CVF THE WEST COAST OF NORTH AMERICA. 553 



485. Ampliidesma bicolor = Semele ?renusta, M. 41 (non A. Ad.)- 



487. Ampliidesma proximum, probably =486, ellipticum, var. : not Semele proximo,, 



M. 4Q, = S.Jlavescens, Gld., M. p. 54S. 



489. Ampliidesma striosum, resembles Semele pulchra, no. 488. 

 491. Ampliidesma ventricosum. Scarcely perfect enough to distinguish the genus. 



The valve outside resembles Macoma solidula. 



497. Anatina alta. A valve of Periploma ; probably one of the Gulf species. 



498. Pandora cornuta, named and described from a fractured growth ; resembles 



Clidiophora claviculata. 

 499 ; 500 are varieties of the same species of Azara, of which perhaps no. 50i is an 



extreme form. 

 506. Corbula rubra= C, biracliata, jun., no. 503, M. 31. No. 509 are dead valves 



of the same,= C. poly chroma, Cpr. 

 508. Corbula, sp. a, resembles C. pustulosa, M. 32. 



510. Solecurtus affinis, probably = S. Caribbceus = Siliquaria gibba, Spengl., S.I. 



Check-List, no. 222. The W. African specimens are affiliated to the same 

 species by Mr. Cuming. The Mazatlan shells, M. 37, have a different 

 aspect, but closely resemble the Ariquibo specimens in Mus. Amherst. 



511. Solen rwlis is named Sokna obliqua, Spengl., in Mus. Gum. It appears iden- 



tical with Ensatella ambiaua, Lam., as figured by Deless. ; but S. amlit/ua 

 (Lam.), Swains., is slightly different, am I better agrees with the dead valves 

 of " & medius, Alatska," in Brit. Mus. These may, however, be only ballast- 

 valves. As S. ambigua, Lam., was described from America, and the form 

 is not known elsewhere, it probably represents the Panamic shell. 



515. Pholas, sp. a, = laqueata. teste Cum. 



516. Pholas, sp. b, closely resembles Daetylina dactylus; also La Paz, teste Rich. 



The following species were collected by Prof. Adams, but do not appcr.r 

 in his Catalogue ; they were found either mixed with others in the Amherst 

 Museum or in the shell- washings of hjs duplicates*. 



528. Coecum clatliratum. 



529. Lepidopleurus tenuisculptus. 



530. Ischnochiton Elenens.s, 



531. Cerithiopsis, n. s. 



532. Lucina capax. 



533. Kellia suborbicularis, 



534. Sphaenia fragilis. 



535. Tellina lamiiuua. 



536. Crenella inflata. 



518. Mumiola ovata. 



519. Chrysallida effusa. 



520. Chrysallida telescopiunu 



521. Chiysallida fasciata. 



522. Chrysallida, n. s. 

 52->. Leiostraca retexta. 

 524. Eulima yod. 



52o. Volutella margaritula. 

 520. Caecum semilaeve. 

 527. Caecum subquadratum. 



55. British Museum Catalogues. To the list of Deshayes, Cat. Veneridce, 

 may be added 



Page. 



7. Dosinia ponderosa, Gray,= Cy^ gigantea, Sby.,= Venus cycloides, D'Orb. 



[Gulf] California. 

 135. Chione callosa [Desh. et auct. K\it.,= Ch.Jluctifraga, var., quite distinct from 



Callista (Amiantis) callosa'], Conr. 

 147. Chione astartoides, Beck, Greenland. [1849. = Tapes fluctuosa, Gld., 1841 ; 



teste Gld., Otia, p. 181. Midd.'s figures more resemble V. Kennerleyi, jun.] 



The authorities are rarely given for localities quoted in this elaborate 

 work. The same species often occur under different names. The Veneridce 



* With regard to the speciee which have received different designations in the Eeigen 

 and Adamsian catalogues, whether those names be retained of which the specimens exist, 

 and have been widely distributed, in accordance with the diagnoses, or whether the prior- 

 ones be adopted of which the unique types do not represent the descriptions, is a matter 

 of little moment to the writer of the Brit. Mus. Cat. He spared no pains in making-out 

 his predecessor's species before describing his own, and has offered the best attainable 

 ligfc of the parallel forms in the review here quoted. 



39 



