312 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



with the prominent tips of the tubes ; this is the Cellei^ora ramulosa, 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 Jilspldum, which 

 forms soft gelatinous incrustations around the stems of Fucus. On the 

 under sides of the stones several additional kinds occur, the most common 

 of which is the Uscliarella varicibilis^ (Plate XXXIII, 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, oft* 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, biding 

 under the loose stones, and nimbly running away when disturbed. It 

 may 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 tbe males may 

 sometimes be witnessed. It is not confined to rocky shores, but is com- 

 mon also on sandy shores, as well as on rock}^ and gravelly bottoms off 

 shore. It is widely diffused along our coast, extending both nortli 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 oliv^e-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 fiattcned above, and is usually a little smaller than the second, 

 the ranopeiis 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 



