152 CLASS CRUSTACEA. 



arching of the edges of the testa terminates posteriorly by a 

 fold, and a projection jutting out in the manner of an angle. 

 Those whose ftont is tridenticulated, and. whose testa pre- 

 sents on each side only this projection or posterior tooth, 

 compose Dr. Leach's genus Carpilius. The species of this 

 subdivision (C. coralUnus, Fab. ; C. macalatus ejusd.) have 

 marblings, or round spots, of the colour of blood, [Xantlio 

 of the same.) Other considerations might induce us to aug- 

 ment the number of these sections. But we have thought 

 proper to confine ourselves to an indication of the principal 

 ones. 



PiRiMELA, Leach, 



Altogether resemble the crabs, but their external antennse 

 are remarkably extended beyond the forehead, and their stem, 

 longer than the pedicle, is composed of a great number of ar- 

 ticulations. The fossets of the intermediate are, as well as in 

 C. pagurus, rather longitudinal than transverse. But one 

 species known, (P. denticulata, Leach.) 



Atelecyclus, Leach, 



Have, as well as the pirimelae, the fossets of the intermediate 

 antennae longitudinal. The lateral antennae are elongated, 

 projecting, and composed of a great number of articulations. 

 But they are very setaceous, as well as the claws ; these claws 

 are strong, with the hands compressed. The third articula- 

 tion of the jaw-feet is sensibly narrowed above, in the manner 

 of an obtuse, or rounded tooth. The tarsi are conical, and 

 the ocular pedicles are of the ordinary size. The tail is more 

 elongated than in the preceding Crustacea. 



