THE SHELL-FISH OF THE COAST. 47 
does not much exceed 18 or 20 fathoms. - Their 
food consists principally of minute larvee, infusori- 
ans, and the lowly-organized plants known as Di- 
atoms, but they do not refuse either crustaceans 
or mollusks, provided these be small enough, and 
even the inorganic earths form part of their nutri- 
tive material. In a general way they might be said 
to be omnivorous. The principal spawning season 
about the Chesapeake extends through the months of 
June and July, but some individuals may be found 
with spawn throughout almost the entire year. The 
eggs, which have been estimated to be contained to 
the extent of 100,000,000 in a single large female, 
measure about the one-five-hundredth of an inch in 
diameter, and give birth to active little creatures, 
the fry, which are early provided with a rudimen- 
tary shell. It appears that under favorable circum- 
stances the fry becomes attached within a day after 
its liberation; in this condition the oyster young is 
known as ‘spat.’ Spawning begins at about the 
age of one year. The notion that oysters are harm- 
ful during all but the so-called seasonable months 
has nothing to support it beyond the fact that in 
the warmer months the flesh loses in general deli- 
cacy and flavor. 
A near ally of the oyster is an irregular lustrous 
shell, about one inch in diameter, which more gen- 
erally occurs black or bluish-black on our coast, and 
is known to conchologists as Anomia (Pl. 3, Fig. 
8). It is rarely found with both valves attached, 
the valve commonly found being the upper convex 
