NORTHWEST COAST MARINE SHELLBEARING MOLLUSKS. 33 
Superfamily CHAMACEA. 
Family CHAMIDAE. 
Genus CHAM A 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. 149 ; Trans. Zool. Soc., vol. 5, pi. 38, figs. 1, 2. 
San Diego, California, to Pern. 
CHAMA BUDDIANA C, B. Adams, 1850. 
Panama Shells, p. 253. 
Bodega Bay, California, to Panama. 
Genus PSEUDOCHAMA OdhneB, 1917. 
PSEUDOCHAMA EXOGYRA Conrad, 1837. 
.Tourn. Acad. Nat. Sci. Phila., vol. 7, p. 256; Conch. Icon. Cluima, 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, fig. 10; Proc. U. S. Nat. Mus., 
vol. 17, pi. 26, figs. 2, 5. 
Off Alaska Peninsula and southward to Oregon coast. Also Miocene and 
Pliocene. 
THYASIRA GOULDII Philippi, 1845. 
Zeitschr. Mai., vol. 2, p, 74; Biimey’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 Dali, 1916. 
Proc. U. S. Nat. Mus., vol. 52, No. 2183, p. 409. 
Southeastern Alaska. 
