34 RECENT BIVALVE MOLLUSKS 



Protothaca staminea var. orhclla Carpenter, 1864. 



Kadiak Island, Alaska, to San Dieg-o, Cal. 

 Protothaca staminea var. spatiosa Dall, 1916. 



Puget Sound to Anaheim Bay, Cal. 

 Protothaca grata Say, 1831. 

 Q>. San Pedro (Williamson). Gulf of Cal. to Panama. 



Genus Liocyma Dall, 1870. 



Liocyma beckii Dall. 1870. 



Arctic Ocean at Point Barrow, and southward to Bering 



Sea and North Japan, on the east to Port Althorp, Alaska. 

 Liocyma scammoni Dall, 1871. 



Port Simpson, British Columbia. 

 Liocyma viridis Dall. 1871. 



Arctic Sea southward to North Japan, and on the east to 



the Kadiak Islands, Alaska. 



Genus A'enerupis Lamarck. 1818. 



Venerupis lamellifera Conrad, 1837. 

 Monterey to San Diego, Cal. 



Sitbfauiily Gemminae 

 Genus Gemma Deshayes, 1853. 



Gemma gemma Totten, 1834. 



San Francisco Bay. Introduced from the Atlantic coast 

 with "seed" oysters. (San Diego?) 



Genus Psephidia Dall, 1902. 



Psephidia lordi Baird, 1863. 



Unalashka, Alaska, to Coronado Islands. 

 Psephidia ovalis Dall, 1902. 



St. Paul Island, Bering Sea, to San Diego, Cal. 

 Psephidia cymata Dall, 1913. 



Santa Barl)ara Islands, Cal.. to Gulf of California. 

 ? Psephidia salmonea Carpenter, 1864. 



Catalina Island to San Diego, Cal. 

 Psephidia brunnea Dall, 1916. 



Monterey, Cal., to San Ipolito Point, Lower California. 



Family Petricolidse 

 Genus Petricola Lamarck, 1801. 



Petricola carditoides Conrad, 1837. 



Vancouver Island to Lower California. 



