MOLLUSCA. 
57 
Section II. MOLLUSCA (proper). 
The Mollusca are chiefly procured by dredging, examina¬ 
tion between tide-marks, or the deep-sea lines of the fisher¬ 
men, though certain storms sometimes strew the sands with 
many species in great profusion. Not a few of the rarer forms 
are found in the stomachs of fishes, such as the cod, haddock, 
and flounder. The remarks on the class may be arranged in 
three divisions, founded on the economical value, peculiar 
habits, and rarity. 
By far the most important species in the first group is the 
common mussel (Mytilus edulis) } which occurs in vast numbers 
in the form of mussel-“ beds ” on muddy flats, chiefly situated 
on the right bank of the estuary of the river Eden. Attached 
to stones, sticks, and to each other, these shell-fish luxuriate 
in abundance of Diatomacege, Infusoria, and other minute 
forms of animal and vegetable life. From their special value 
as bait the city derives a considerable annual revenue; and if 
the wise protection only lately enforced were supplemented by 
skilful mussel-farming, great increase in. revenue might be 
anticipated. Shell-fish, like other animals in civilized parts, 
cannot survive constant inroads without special restrictions. 
Multitudes of the young mollusks, moreover, are found in- 
crusting the poles for the salmon-nets on the West Sands, and 
the rocks, stones, and tangle-roots elsewhere; but they do not 
attain a large size, apparently from overcrowding and the want 
of congenial food, which the purer water seems incapable of 
supplying. This species takes the place of the horse-mussel 
(“yoags ”) of the Zetlandic fishermen, and the worms of those 
in the Channel Islands. It is seldom eaten by the natives. The 
edible cockles, again, abound on the sandy flats near the 
entrance of the Eden into the sea, and are occasionally sold as 
food, though of late years their scarcity has rendered their 
appearance less frequent in the market. Periwinkles and 
limpets are constantly gathered for similar purposes. The 
I 
