106 



WEST COAST SHELLS 



Spisula polymyina^ var. alaskana, Dall, the Alaska 

 Mactra, resembles Mactra californica, but is larger. 

 It is found about Icy Cape, but it comes southward 

 as far as Neah Bay. 



Fig. 83. X g 



Spisula catilliformis, Conr., the Dish-shell, for- 

 merly known as Standella Califomica^ is shown in 

 Figure 83. This is the fine large shell which is said 

 to exist from Neah Bay to San Diego. I have col- 

 lected large specimens at Long Beach, Cal. The 

 shell itself is thin, whitish, and is covered with a 

 gray, wrinkled epidermis. The cartilage pit is large 

 and its shape is triangular. The pallial sinus reaches 

 nearly to the middle of the shell. These great Dish- 

 shells sometimes reach a length of over five inches, 

 and can hardly be mistaken for any other species, 

 except the next. 



Spisula hefnphillii, Dall, Hemphill's Mactra, is a 

 rare species occurring in San Pedro Bay and at San 

 Diego. It resembles the last species, but grows even 



