18 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [312] 
with the prominent tips of the tubes; this is the Celleporaramulosa, and 
like the Crisia it is a northern species, which inhabits also the shores 
of northern Europe. Still other species of bryozoa occur in these situ- 
ations. One of the most abundant is Alcyonidium hispidum, which 
forms soft gelatinous incrustations around the stems of Mucus. On the 
under sides of the stones several additional kinds occur, the most common 
of which is the Hscharella variabilis, (Plate XX XIII, fig. 256,) which 
forms broad calcareous crusts, often several inches across, and of some 
thickness, composed of small perforated cells. While living this species 
is dark-red or brick-red, but it turns green when dried, and then 
fades to yellow, and finally to white. It is far more abundant on shelly 
bottoms, off shore, in 3 to 10 fathoms of water, and in such places often 
covers every stone, pebble, and shell, over wide areas, and in some 
cases forms rounded coral-like masses two or three inches in diameter 
and more than an inch thick. 
Crustacea in considerable numbers may also be found upon the 
rocky shores. Of crabs four or five species are common, concealed 
under the rocks and in crevices. The “green crab,” Carcinus granu- 
latus, occurs quite frequently well up toward high-water mark, hiding 
under the loose stones, and nimbly running away when disturbed. It 
nay also be found, at times, in the larger tidal pools. Its bright green 
color, varied with spots and blotches of yellow, makes this species quite 
conspicuous. The common ‘“rock-crab,” Cancer irroratus, is generally 
common under the large rocks near low-water mark and often lies 
nearly buried in the sand and gravel beneath them. This species is 
usually larger than the preceding, often becoming three or four inches 
across the shell, and though less active it uses its large claws freely 
and with force. It can be easily distinguished by having nine blunt 
teeth along each side of the front edge of its shell or carapax, and by 
its reddish color sprinkled over with darker brownish dots. This crab 
also occurs in the pools, where the comical combats of the males may 
sometimes be witnessed. It is not confined to rocky shores, but is com- 
mon also on sandy shores, as well as on rocky and gravelly bottoms off 
shore. Itis widely diffused along our coast, extending both north and 
south, and is common even on the coast of Labrador. Like all the 
other species of crabs this is greedily devoured by many of the larger 
fishes, such as cod, haddock, tautog, black-bass, and especially by 
sharks and sting-rays. Two smaller kinds of crabs are also very abun- 
dant under the stones, especially where there is some mud. These are 
dark olive-brown and have the large claws broadly tipped with black- 
They are often called mud-crabs on account of their fondness for muddy 
places. One of these, the Panopeus depressus, (Plate I, fig. 3,) is decid- 
edly flattened above, and is usually a little smaller than the second, 
the Panopeus Sayi, which is somewhat convex above. They are usually 
found together and have similar habits. A third small species of the 
same genus is occasionally met with under stones, but lives rather 
