CLASS PELECYPODA. 



ORDER PRIONODESMACEA 

 (FOLIOBRANCHIATA) 



Super family Solenomyacea 



Family Solemyacidas 



Genus vSoIemya Lamarck, 1818. 



Siihzeiuis Acharax Dall, 1908. 



Acharax johnsoni Dall, 1891. 



Oregon to Panama. 

 Acharax agassizii Dall, 1908. 



Tillamook to Agaija Point, Peru. 



Subgenus Petrasma Dall, 1908. 



Petrasma panamensis Dall, 1908. 



Santa Barbara, Cal., to Panama. 

 Petrasma valvulus Carpenter, 1864. 



San Pedro, Cal., to Gulf of California. 



Superfamily Nuculacea 



Family Nuculidse 



Genus Nucula Lamarck, 1799. 



Nucula tenuis Montagu, 1808. 



Point Barrow to Coronado Islands. Circumboreal. 

 Nucula tenuis, variety e.vpansa Reeve, 1855. 



Arctic Ocean to Sitka, Alaska; San Diego? 

 Nucula quirica Dall, 1916. 



Chugachik Bay, Cook's Inlet, Alaska. 

 Nucula petriola Dall, 1916. 



Off Santa Rosa Island, Cal., in S3 fathoms. 

 Nucula cardara Dall, 1916. 



Monterey, Cal., to Lower California. 

 Nucula linki Dall, 1916. 



(.)ueen Charlotte Sound to Guavmas, Mexico. 



