VENERIDAE 417 



storms between Seal Beach and Huntington Beach. Once known as C. 

 nobilis Reeve. 



Genus Saxidomus Conrad 1837 



Shell large, slightly gaping posteriorly, hinge with 4 or 5 cardinal teeth 

 in the right valve, 4 in the left. Pallial sinus long and fairly narrow. 



Saxidojims nuttalli Conrad Common Washington Clam 



Plate 31I 



Humboldt Bay, California, to Lower California. 



3 to 4 inches in length, oblong, with the beaks nearer the anterior end; 

 heavy, with coarse, crowded, concentric ribs. Color a dull, dirty, reddish 

 brown to gray with rust stains. Interior glossy-white, commonly with a 

 flush of purple at the posterior margins. No lunule. Ligament large. Valves 

 slightly gaping posteriorly. Young specimens less than 2 inches are thin- 

 shelled, somewhat glossy and with pretty, mauve, radial streaks on the dorsal 

 edge, both in front and behind the beaks. A very common species which is 

 edible. Also called the Butter Clam. 



Saxidomus gigantea Deshayes Smooth Washington Clam 



Aleutian Islands to Monterey, California. 



Possibly this is only an ecologic variation or an example of a geographical 

 gradient within a species. It is similar to typical 7JUttalIi, but generally lacks 

 the rust-stain color and rarely, if ever, develops the prominent concentric 

 ridges. This is the commonest and best food clam in Alaska. 



Subfamily DOSINIINAE 



Genus Dosinia Scopoh 1777 



Subgenus Dosinidia Dall 1902 



Dosinia elegajis Conrad Elegant Dosinia 



West Florida to Texas and south. 



2 to 3 inches in length, circular, compressed, glossy, straw-yellow with 

 numerous even, concentric ridges (20 to 25 per inch in adults). Moderately 

 common. Do not confuse with D. discus. 



Dosinia discus Reeve Disk Dosinia 



Plate 38-0; figure 81 c 



Virginia to Florida, the Gulf States and the Bahamas. 



