74 



GENUS ATELECYCLUS: Carapace large, arched anteri- 

 orly, more contracted behind. Cavities of the antennae 

 longitudinal, the front denticulated. 

 BIDENTICULATED CRAB. A. Heterodon. M. Edwards' 

 Crust., vol. 2, p. 143. 



Common in the stomachs of fishes, chiefly Cod fishes and 

 Rays, from the depth of 20 to 50 fathoms. They must abound 

 at these depths, as I have found more than thirty in a single 

 fish, and almost every Ray opened for several days in succes- 

 sion was found to contain them. 



GENUS CORYSTES: Carapace much larger than wide, 

 and in shape approaching to an ellipse. Outer Antennas 

 very long, and inserted in a cavity of the orhitary foramen. 



LONG CRAB. C. Dentatus. M. Edwards' Crust , vol. 2, p. 

 148. C. Cassivalaunus, Leach's Malac, pi. 1. Cancer, C. 

 Pennant, pi. 7. C. Personatus of some writers. 



It is scarcely common, which may be accounted for from its 

 habit of burrowing in the sand, leaving the extremities of its 

 antennae alone projecting above the surface. These organs 

 are of some use beyond their common office of feelers; per- 

 haps as in some other Crustaceans, tbey assist in the process 

 of excavation ; and when soiled by labour I have seen the Crab 

 effect their cleaning by alternately bending the joints of their 

 stalks, which stand conveniently angular for this purpose. 

 Each of the long antennae is thus drawn along the brush that 

 fringes the internal face of the other, until both are cleared of 

 every particle that adhered to them. 



FAMILY of ANOMOURS. 

 PTERYGURES, a subfamily having a pair of moveable ap- 

 pendages at the extremity of the abdomen. 



PAGURIANS, or HERMIT CRABS. 



GEXUS PAGURUS: the abdomen large and membranous, 

 turned sideways; the pairs of abdominal feet irregular. 



HERMIT CRAB. P. Bernard us. M. Edwards' Crust., vol. 

 2, p. 215. P. Streblonyx, Leach's Malac, pi. 26. Pennant, 

 pi. 17. 



Common and abundant, the smaller in pools left by the tide, 

 the larger in a considerable depth of water; where tbey be- 

 come so large as to occupy Whelk shells (Buccinum) of the 

 largest size : for as Crabs of this genus are weak and de- 

 fenceless on the hinder parts of their body, they exercise the 

 well known habit of residing in the empty shells of various 

 species of the turbinated family ; moving about in this cover- 

 ing, from the earliest ascertained stage of their existence, as if 

 the structure were a portion of their own bodies. They 



