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 
Clift House, in San Francisco. 
Mya arenaria , 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 1849, 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 Mya 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, no 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 liinge-tooth, in the bowl of 
which is the ligament. 
