OF THE NORTHWEST COAST OF AM.ERICA 37 



Macoma quadrana Dall, 1916. 



Boca de Quadra, Alaska, and south to Coronado Islands, 



Lower California. 

 Macoma carlottensis Whiteaves, 1880. 



Arctic Ocean to Puget Sound. 

 Macoma liotricha Dall. 1897. 



Aleutian Islands and eastward to the Shumagin Islands, 



Alaska. 

 Macoma expansa Carpenter, 1865. 



Puget Sound to San Pedro Bay, Cal. 

 Macoma yoldiformis Carpenter, 1864. 



Fuca Strait to San Diego, Cal. 

 Macoma truncaria Dall, 1916. 



Island near Cape Halkett, Arctic Ocean. 

 Macoma alaskana Dall, 1900. 



Lituya Bay to Sitka, Alaska. 



Section Rexithjerus Conrad. 1869. 



Macoma indentata Carpenter, 1866. 



Santa Barbara. Cal.. to Lower California. 

 Macoma indentata var. tcnuirostris Dall, 1900. 



San Pedro and the Santa Barbara Islands, to San Diego 



( Kelsey). 

 Macoma secta Conrad, 1837. 



A'ancouver Island and south to the Gulf of Cal. Japan? 



Family Semelidas 

 Genus Semele Schumacher, 1817. 



Semele decisa Conrad, 1837. 



San Pedro to San Diego, Cal. 

 Semele striosa C. B. Adams, 1852. 



Catalina Island. Cal.. to Panama. 

 Semele rupicola Dall. 1915. 



Santa Cruz. Cal., to Gulf of California. 

 Semele rubropicta Dall. 1871. 



h'orrester Island, Alaska, to Tia Juana, Lower California. 

 Semele pacifica Dall, 1915. 



Catalina Island, Cal., to Acapulco. 

 Semele incongrua Carpenter, 1863. 



Monterey. Cal.. to the Coronado Islands. 

 Semele pulchra Sowerby. 1832. 



Monterey, Cal.. to Ecuador. 



