766 NATURAL HISTOEY OF AQUATIC ANIMALS. 



Pinnotheres ostreum is eaten both raw and cooked, either along with the oysters with which it 

 is associated, or as a separate dish. It is also pickled for domestic use and for the trade. 



Another species of Pinnotheres (P. maculatum) frequently occurs in the shells of the common 

 sen-mussel (Mytilus edulis) and the smooth scallop (Pecten tenuicostatus), between the gills of the 

 animal. It attains a larger size than the Oyster-crab, and, as in the case of the latter, the females 

 alone are parasitic, the males having only been found swimming at the surface of the sea. We 

 have never heard of this species being eaten, probably because- neither the mussel nor the smooth 

 scallop has ever been used much as food in this country. In the summer of 1880, while dredging 

 off Newport, Ehode Island, the United States Fish Commission steamer Fish Hawk came upon 

 extensive beds of the smooth scallop, from a bushel of which nearly a pint of these Crabs were 

 obtained. Again, in 1881, the same species was encountered in great abundance by the same 

 party, in Vineyard Sound, in Mytilus edulis. As an experiment, they were cooked along with the 

 mussels and found to be very palatable, although their shell is, perhaps, somewhat harder than 

 that of Pinnotheres ostreum. 



A third species of Pinnotheres occurs upon the west coast of the United States, in the shells of 

 Pachydesma and Mytilus calif or nianus. 



THE BOCK CRAB CANCER IRRORATUS, Say. 



DISTRIBUTION AND HABITS. This is the common Crab of the New England coast, where 

 adult specimens occur in all depths of water from low-tide level to about twelve fathoms 

 Smaller specimens have, however, been obtained in from thirty to fifty fathoms, both near 

 the coast and on George's Bank, Stellwagen's Bank, and elsewhere. Its entire range, so far 

 as determined, is from the Straits of Belle Isle, Labrador, to South Carolina. In the Gulf of 

 Saint Lawrence it is exceedingly abundant, but south of New Jersey it is rare. According to 

 Prof. S. I. Smith, 1 this species is not common in the muddy bays of the New Jersey coast, but 

 is thrown up in large numbers upon the sandy outer beaches; it is abundant on the sandy shores 

 of the southern side of Long Island, and on the sandy and rocky shores of Long Island Sound ; 

 it is equally abundant, in similar situations, along all the rest of the south coast of New 

 England and in Cape Cod, Massachusetts, and Casco Bays, but is apparently less common in 

 the Bay of Fundy and at Halifax, Nova Scotia. " When found living between tides it is usually 

 concealed among rocks or buried beneath the sand. It is usually much more abundant at or just 

 below low-water mark, however, than between tides.'' 



"The common 'Bock 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. 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 common also on sandy shores, as well as on rocky and gravelly 

 bottoms off shore. It is 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, tantog, black bass, and especially 

 by sharks and sting-rays." 2 



EXTERNAL CHARACTERS. The carapax of the Eock Crab is transversely suboval in outline, 

 and about two-thirds as long as broad; the upper surface is moderately convex, with unequal 



'Trans. Conn. Acad., v, p. 38, 1879. 'VEEBILL: Vineyard Sound Report, p. 312, 1871-'72. 



