58 CALIFORNIA SEA SHELLS. 



inches, and is covered with a glossy, rich brown 

 epidermis, which shields the thin and delicate 

 shell. The hinge area is strengthened by a stout 

 rib, which runs nearly across the shell. This 

 brace presents a mo-t evident mark of design, tor 

 it exactly tits its purpose. This species abounds 

 in the north, and is considered delicious food. 

 Broken shells may often be picked up near the 

 Cliff House, in San Francisco. 



My a arena ria, Linn., well known in the mar- 

 kets of San Francisco, as the " Soft-shelled 

 Clam," is not a native of this fine country, but, 

 like the Argonauts of 18-L9, it came, enjoyed, 

 settled, and multiplied. We find no trace of its 

 shells in the old Indian mounds, and the first of 

 the species were doubtless brought with Eastern 

 oysters, and planted in San Francisco Bay. Un- 

 like the oysters, however, the My a has reproduc- 

 ed its kind with startling rapidity, and though 

 it is only seven years since the first specimens 

 were discovered in our waters, they might now 

 be gathered by the million. Their holes may be 

 seen all over the muddy flats, when the tide is 

 out, and they can easily be captured by digging 

 one or two feet deep. Although to us a soli- 

 tary position in the depths of black mud would 

 seem the acme of all disagreeable situations, our 

 friend, M. arenaria, thrives in it remarkably, 

 and is, uo doubt, " as happy as a clam." 



The shell is oblong, thin and brittle, gaping, 

 whitish, and covered near the edge with a gray 

 epidermis. Its most conspicuous peculiarity is 

 the flat, spoon-shaped hinge-tooth, in the bowl of 

 which is the ligament. 



