_Trout_, in spite of the difference in size, may be judged by the
same rule as salmon. However, it will not bear keeping, deteriorating
rapidly.

_Cod_, unlike salmon, should have a large head and thick shoulders;
the flesh being white and clear, and separating easily into large
flakes, the skin clean and silvery. Most people consider cod improves
by being kept for a day or two and very slightly salted.

_Herrings_ must be absolutely fresh to be good, and when in this state
their scales shine like silver. If kept over long their eyes become
suffused with blood.

_Mackerel_ also must be quite fresh. They never should be bought
if either out of condition or season. If fresh they are peculiarly
beautiful fish, their backs of an iridescent blue green barred with
black, and their bellies of a pearly whiteness.

_Smelts_ should be stiff and silvery, with a delicate perfume faintly
suggestive of cucumber.

_Halibut_ is a wholesome fish. It should be middling size, thick and
of a white color.

_Lobsters, Crabs, Prawns, and Shrimps_ are stiff, and with the tails
tightly pressed against the body. With the former, weight is a great
guide, as the heavier they are the better; but if there be the least
sign of wateriness, they should be rejected at once.