iS^OETHWEST COAST MAEUSTE SHELLBEAKING MOLLUSKS. 53 
MYA ARENARIA Linnaeus, 1758. 
Syst. *Nat, ed. 10, p. 670; Binney’s Gould’s Inv. Mass., p. 55, fig. 375. 
Introduced at San Francisco with “ seed ” oysters from- the Atlantic 
coast. Spread from Victoria, British Columbia, to Monterey, California. 
Genus CRYPTOMYA Conrad, 1849. 
CRYPTOMYA CALIFORNICA Conrad, 1837. 
Journ. Acad. Nat. Sci. Phila., vol. 7, p. 234, pi. 17, fig. 11. 
ChichagofC Island, Alaska, and south to Topolobampo, Mexico. 
Genus SPHENIA Turton, 1822. 
SPHENIA FRAGILIS Carpenter, 1857. 
Mazatlan Cat., p. 24, No. 35. 
Oregon to Mazatlan. 
SPHENIA OVOIDEA Carpenter, 1864. 
Suppl. Rep. Brit. Assoc., p. 637 ; Proc. Acad. Nat. Sci. Phila. for 1865, p. 54. 
Aleutian- Islands to Puget Sound and San Diego. 
SPHENIA TRUNCULUS Dali, 1916. 
Proc. U. S. Nat. Mus., vol. 52, No. 2183, p. 415. 
San Diego, California, to Panama. 
SPHENIA PHOLADIDEA Dali, 1916. 
Proc. U. S. Nat. Mus., vol. 52, No. 2183, p. 415. 
Santa Barbara, California. 
SPHENIA GLOBULA Dali, 1919. 
Proc. U. S. Nat. Mus., vol. 56, No. 2295, p. 570. 
Monterey, California. 
Genus PLATYODON Conrad, 1837. 
PLATYODON CANCELLATUS Conrad, 1837. 
Journ. Acad. Nat. Sci. Phila., vol. 7, 236, pi. 18, fig. 2. 
Baulinas Bay, California, to San Diego, California. ^LuILcx^ ^ 
Family CORBULIDAE. 
Genus CORBULA Bruguiere, 1792. 
CORBULA OBESA Hinds, 1843. 
Proc. Zool. Soc., p. 57 ; Zool. Sulphur'' s Voy., Moll., p. 68, pi. 20, fig. 12. 
Catalina Island, California, to Panama. 
CORBULA FRAGILIS Hinds, 1843. 
Proc. Zool. Soc., p. 56; Zool. Sulphur's Voy., Moll., p. 68, pi. 20, fig. 11. 
INIonterey, California, to Salina Cruz, Mexico. 
CORBULA LUTEOLA Carpenter. 1864. 
Suppl. Rep. Brit. Assoc., p. 637 ; Proc. Cal. Acad. Sci., vol. 3, p. 207.— 
Aenold, Pal. San Pedro, p. 181, pi. 17, fig. 11. 
Monterey, California, to Magdalena Bay. 
