OF THE XORTHWEST COAST OF AMERICA 31 



Cerastoderma fucanum Dall. 1907. 



Southern Bering- Sea, off Unimak Island, and south to 

 Fuca Straits. 



? Sitbgcnns Ring-icardium Fischer, 1887. 



Ringicardium procerum Sowerby, 1833. 



Pleistocene, San Diego. Cerros Island to Payta, Peru. 



Subgenus Fragimi Bolten, 1798. 



Fragum biangulatum Sowerby, 1829. 

 San Pedro. Cal., to Panama. 



Subgenus Trigoniocardia Dall, 1900. 



Trigoniocardia eudoxia Dall, 1916. 



Catalina Island, Cal., to Gulf of California. 



Subgenus Laevicardium Swainson, 1840. 



Laevicardium datum Sowerby, 1833. 



San Pedro, Cal., south to Panama. 

 Laevicardium substriatum Conrad, 1837. 



Latalina Island and San Pedro. Cal., to Acapulco. 



Genus Serripes Beck, 1841. 



Serripes gronlandicus Gmelin, 1792. 



Circumboreal. Arctic Seas and south to Hakodate, Japan, 



and Puget Sound. 

 Serripes laperousei Deshayes, 1839. 



Bering Strait to Hakodate, Japan, and Sitka, Alaska. 



Genus Protocardia Beyrich, 1845. 



Protocardia centifilosa Carpenter, 1864. 



Bodega Ba}' to Lower California. 

 Protocardia centifilosa var. richardsonii \Yhiteaves, 1878. 



Queen Charlotte Islands to San Francisco. 



Fouiily \^esicomyacida; 

 Genus Vesicomya Dall, 1886. 



Vesicomya ovalis Dall, 1895. 



Clarence Strait, Alaska, 322 fathoms, and in Panama Bay, 

 in 1672 fathoms. 



Vesicomya lepta Dall, 1895. 



(JIT Tillamook, Oregon, and south to the Gulf of Califor- 

 nia, in deep water. 



Vesicomya stearnsii Dall. 1895. 



Oft" La Jolla, Cal., and south to the Gulf of California, in 

 deep water. 



