NORTHWEST COAST MARINE SHELLBEARING MOLLUSKS. 33 



Superfamily CHAMACEA. 



Family CHAMIDAE. 

 Genus CHAMA Linnaeus, 1758. 



CHAMA PELLUCIDA Sowerby, 1834. 



Proc. Zool. Soc, p. 150.— Keep, West Coast Shells, fig. 155. 

 Oregon to Chile, and Galapagos Islands. 



CHAMA FRONDOSA Broderip, 1834. 



Proc. Zool. Soc, p. 141); Trans. Zool. Soc, vol. 5, pi. 38, tigs. 1, 2. 

 San Diego, California, to Peru. 



(HAMA BUDDIANA C. B. Adams, 1850. 

 Panama Shells, p. 253. 

 Bodega Bay, California, to Panama. 



Genus PSEUDOCHAMA Odhner, 1917. 

 FSEUDOCHAMA EXOGYRA Conrad, 1837. 



Journ. Acad. Nat. Sci. Phila., vol. 7, p. 256; r'onch. Iron. Chama, pi. 7, 



fig. 38. 

 Oregon to Panama. 



Superfamily LUCINACEA. 

 Family THYASIRIDAE. 



Genus THYASIRA (Leach in) Lamarck, 1818. 



THYASIRA BISECTA Conrad, 1849. 



Rep. U. S. Expl. Exp., vol. 10, p. 724, pi. 17, iig. 10; Proc U. S. Nat. Mus., 



vol. 17, pi. 26, figs. 2, 5. 

 Off Alaska Peninsula and son:; ward to Oregon coast. Also Miocene and 



Pliocene. 



THYASIRA GOULDII Philippi, 1815. 



Zeitschr. Mai., vol. 2, p. 74; Binney's Gould's Inv. of Mass., p. 100, fig. 206. 

 Bering Strait to San Diego. Also Atlantic. 



THYASIRA TRISINUATA Orbigny, 1846. 



Moll. Cuba, vol. 2, p. 300, pi. 27. figs. 46, 49. 



Sitka, Alaska, to San Diego, California. Also Atlantic 



THYASIRA TRISINUATA POLYGONA Jeffreys, 1863. 



British Conch., vol. 2, p. 248. 



Korea. Gulf of Alaska to San Diego. Also Atlantic. 



THYASIRA CYGNUS Dall, 1916. 



Proc U. S. Nat. Mus., vol. 52, No. 2183, p. 409. 



Southeastern Alaska. 



