30 RECENT BIVALVE MOLLUSKS 



Genus Turtonia Alder, 1848. 



Turtonia minuta Fabricius, 1780, 



Bering Strait and south to Magdalena Bay, Lower Ca!., 



also Northern Atlantic. 

 Turtonia occidentalis Dall, 1871. 



Plover Bay, Bering Sea. 



Genus Sportella Deshayes, 1858. 



Sportella californica Dall, 1899. 

 Monterey, Cal. 



Genus Anisodonta Deshayes, 1858. 



Anisodonta? pellucida Dall, 1916. 



Monterey Bay, Cal., off Del Monte. 



Family Chlamydoconchidze 

 Genus Chlamydoconcha Dall, 1884. 



Chlamydoconcha orcutti Dall, 1884. 

 False Bay, San Diego Co., Cal. 



Superfamily Cardiacea 



Family Cardiidse 



Genus Cardium Linne, 1758. 



Subgenus Trachycardium M5rch, 1853. 



Trachycardium quadragenarium Conrad, 1837. 



Santa Barbara, Cal., to Todos Santos Bay, L. Cal. 



Subgenus Cerastodernia Morch, 1853. 



Cerastoderma corbis Martyn, 1784. 



Nunivak, Pribiloft', and Commander Islands, Bering Sea, 



south to Hakodate, Japan, and San Diego, Cal. (Lower 



Cal. ?) 

 Cerastoderma ciliatum Fabricius, 1780. 



Circumboreal. Arctic Ocean and southward to Puget 



Sound and North Japan. 

 Cerastoderma decoratum Grewingk, 1850. 



Pleistocene of Alaska and British Columbia. Recent? 

 Cerastoderma californiense Deshayes, 1839. 



Arctic Uccan to San Diego, Cal., North Japan and 



Okhotsk Sea. 

 Cerastoderma californiense var. couioxense Dall, 1900. 



Pleistocene of Vancouver Island. Recent? 



