OTHER BIVALVE MOLLUSKS 95 
Mactra nasuta, Gld., 
the Beaked Mactra, re- 
sembles Figure 84, a fig- 
ure which shows the gen- 
eral internal appearance 
of several species of 
this group. The shell is 
of moderate size, and is 
widely seattered along the coast. 
Mactra californica, Conr., the California Mactra, 
(Standella nasuta), has a rather small shell, some- 
what depressed behind the furrowed beaks, which 
are near the center of the shell. An inch to an inch 
and a half in length. 
Mactra dolabriformis, Conr., the Mattock Mac- 
tra, occurs from San Diego southward, and so 
scarcely comes into our list. The shell is com- 
pressed; and is polished white under a dull brown 
epidermis. In the hinge-area the ligament is sep- 
arated from the cartilage pit by a shelly plate. 
This fine shell grows to a length of three and a half 
inches. 
Spisula polymyma, var. alaskana, Dall., the 
Alaska Mactra, resembles M. californica, but is 
larger. It is found about Icy Cape, but comes 
southward as far as Neah Bay. 
Spisula catilliformis, Conr., the Dish-shell, 
(Standella Californica), is shown in Figure 85. 
This is the fine large shell that is said to exist from 
Neah Bay to San Diego. I have gathered large 
specimens about Long Beach, Cal. The shell is 
