— 45 — 



Habitat and habits— Accordiiig to Thompson* in British Columbia 

 it is found lying on its left side at a depth of a foot and a half in 

 pure sand on the exposed portion of the larger flats. "The flesh of 

 this species is very delicate, and when steamed is white and very 

 little like a clam. " The alimentary canal is invariably full of sand, 

 however, and the utilization of this form awaits a method of ridding 

 the animal of this." This could probably be done by holding for a 

 time in tanks as described in the case of the bent-nosed clam. 



Distribution and use — Living specimens were obtained only at 

 :\b)rr() liav. though the shells are common at many points and its 

 r;ing(> includes all of the California coast. As far as known it is not 

 used at any point. 



FLAT CLAM 



Seniele decisa Conrad 

 Plate 13, figure 2 



Description — Though there are several species of this genus on 

 the coast, only one, Semele decisa, reaches a size (two and a half to 

 three inches) rendering it of use as food. The valves are nearly round 

 in outline, firm and fairly heavy, little arched and diiferent on the 

 two sides at the siphonate end. 



The ligament is fairly large and external, the cartilage larger and 

 internal, being lodged in an oblique pit distinctly diiferent from any 

 other form here treated. The pallial sinus is large and rounded. 

 Exteriorly the shell is roughened, giving a granular effect ; it is faintly 

 tinged with pink and shows more or less of a brown periostracum. 

 Within, the valves are tinged with a faint purple particularly near 

 the margins, making in all a very handsome shell. 



Use— Its use was not observed, though in "Fisheries and Fishery 

 Industries of the United States" (Washington, 1893, p. 708) it is listed 

 as one of the Pacific coast edible species. It is not at present abundant 

 enough to be of economic importance. 



SUNSET SHELLS 



Psammobia calif or nica Conrad 



Plate 14, figure 1 



Psammobia cdentula Gabb 



These two species of PsammoUa reach a size large enough to make 

 possible their use as food, though neither are of importance in this 

 regard. 



Description— The valves are little arched and fit loosely together. 

 The siphons are separate and very long and the pallial sinus is 

 correspondingly large. The two species ditfer chiefly in size and shape. 



* Report on the Clambeds of British Columbia. Report of the B. C. Commissioner 

 of Fisheries, 1912, p. 41. 



