132 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 
resent the allowance for an ordinary voyage of a vessel of from 50 to 
75 tons. Of late years clams have been less in demand for cod-fish- 
ing, fresh herring purchased near the grounds or pickled herring being 
more extensively used. 
(11) Mussels, Oysters, and Scallops.—Of the mussel there are two dis- 
tinct species, both known under the same name, and, although gener- 
ically distinct, having a very close external resemblance which prevents 
their being distinguished by the ordinary observer. One of these is the 
Mytilus, the other the Modiola. These are well-known inhabitants of 
the waters, being found attached in great numbers to the piles of piers, 
and to rocks, gravel, mud, and any other object to which their byssus 
will adhere. They are a favorite article of food in some parts of the 
world, being used largely in Europe for this purpose; but they are less 
esteemed in the United States. Occasionally very grave inconveni- 
ences result from poisoning, of greater or less intensity, being produced 
by them. In view of the well-known fecundity of the mussle, it may 
be imagined that the spat in regions where they abound constitutes a 
very important element in the food of young fish, and the contents 
of the towing-net are very frequently composed largely of extremely 
minute mussels, which are greedily devoured by a great variety of spe- 
cies. 
The oyster is not often used as bait. It is almost too valuable to be 
wasted in this way, and is of so soft and delicate a texture as i break 
away from the hook with but a slight touch. 
The common scallop, Pecten irradians, which is extremely abundant 
off the coast of the Middle and Northern States, is largely utilized 
for food, and only occasionally used as bait for fish. 
(12) Lobsters, Crabs, Shrimps, etc.—The lobster constitutes a very at- 
tractive bait in the small fisheries ; but it is too valuable in itself as an 
article of commerce, to be employed to any great extent. Frequently, 
however, young lobsters, not marketable, or falling within prohibited 
limits of the legal enactments of certain States, are used for capturing 
shore fishes. 
Along the coast of the South Atlantic and Middle States a very 
favorite bait for the ordinary shore fishes is the common blue crab (Cal- 
linectes hastatus) a species occurring in enormous abundance, and con- 
stituting a favorite article of food, whether as hard or soft shell. This 
is a great resource to the fishermen, few fish resisting its attractions, 
especially when the old shell has been thrown off, leaving only a soft 
skin behind. Diminishing in abundance towards Cape Cod, its place is 
supplied, thence northward, by what is there called the common crab 
(Carcinus menas). This appears to constitute an especial attraction to 
the tautog, and doubtless constitutes its food in the sea in very great 
part. 
Shrimps also are used all along the eastern coast of the United States 
in sea fishing. 
