74 ,ifk CRUSTACEA. 



Hyppolyte, Leach. 



The Hyppolytes only differ from Alpheus in the respective pro- 

 portion of their claws; the second are longer than the first(l). 



The two last following subgenera have this peculiarity; but a sin- 

 gle pair of their feet terminate in a didactyle claw. In the 



AUTONOMEA, RisSO, 



It is the two anterior, which are also distinguished from the 

 others by their size, their thickness, and their disproportion^). In 



Pandalus, Leach, 



The two anterior feet are simple, or hardly bifid; the two following 

 ones are longer, of unequal length and didactyle, the carpus and 

 preceding segment annulated. 



The external foot-jaws are very long and slender, at least in some 

 of them. The anterior projection of the shell is greatly extended, 

 and multidentate(S). 



Sometimes the superior antennas have three threads. 



They have four didactyle claws, the smallest of which are folded 

 up, and an elongated rostrum. 



Pal.emon, Fab. 



Prawns are distinguished from the two following subgenera by 

 their inarticulated carpus; the second feet are larger than the first; 

 the latter are doubled up. A remarkably large species is found in 

 the East Indies, the second claws of which are very long. Tolerably 

 large ones are also found at the Antilles, some of which frequent the 

 mouths of rivers. Those on the coast of France are much smaller, 

 and are known there by the vulgar names of Crevettes and Salicoques. 

 Their flesh is more highly esteemed than that of the Shrimp. Ac- 

 cording to M. de Brebisson Catal. Method, des Crust, terrest. et 

 fluviat., de depart, du Calvados, they are taken in the same manner 

 as the latter Crustacea, but in the summer only. Prawns swim well, 

 particularly when escaping from pursuit, and in various directions. 

 They are. always found about the shore. The lithographic stone of 



(1) To this subgenus should be referred the Pulsemon diversimane, and P. 

 marbre, of Olivier. See Desmar., Consid., p. 220. 



(2) Jluionomea Olivii, Risso, Crust., p. 166; Cancer glaber, Oliv., Zool. Adriat., 

 Ill, 4; Desmar., Consid., p. 251, and 252. 



(3) Pandalus annuUcornis, Leach, Malac. Brit., XL; Pandalus narwal, Latr.; 

 Jlstacus nariualy Fab.; Palxmon pristis, Risso; Cancer armiger? Herbst., XXXIV, 

 4. See Desmar., Consid., p. 219, 220. 



