524 INSECT A. 



These lines are sometimes obliterated, and the individuals in 

 which this occurs are considered by some entomologists as form- 

 ing a separate species the elongatum. No others are known(l). 



In the third and last genus of this tribe, or 



Prionus, Geoff. Fab. Oliv. 



The antennae are longer than the head and thorax, serrated or pec- 

 tinated in some; simple, attenuated near the extremity, and with 

 elongated joints in others. The terminal lobe of the maxillae is at 

 least as long as the two first joints of the palpi. The body is gene- 

 rally depressed, and the thorax square or trapezoidal, and either 

 dentated or spinous, or angular laterally. 



These Insects only fly towards evening or at night, arid always re- 

 main on trees. Certain species foreign to Europe are remarkable 

 for their great size, and that of their mandibles. The larva of the 

 P. cervicoimis, which lives in the wood of the Gossampinus, is eaten. 

 This genus comprises a considerable number of species, which, 

 from the difference in the form and size of their mandibles, antennae, 

 thorax, and abdomen, might constitute several small groups or sub- 

 genera. 



We might, in the first place, separate those species in which the 

 body is straight, elongated, or forms a parallelopiped; the thorax is 

 much shorter than the abdomen, square or trapezoidal, and strongly 

 arcuated laterally; the scutellum is small or moderate,' the antennae 

 are simple or but slightly serrated, and the mandibles frequently 

 large in the males. 



Among the species of this division, with mandibles shorter than 

 the head, the antennae almost setaceous, tolerably long, and composed 

 of eleven joints, the third of which is much longer than the follow- 

 ing ones, we find the 



P. scabricornis, Fab. Oliv., Col. IV, 66, XI, 42. Length an 



inch and a half; antennae bristled with small spines; a single 



tooth on each side of the thorax formed by its posterior an- 



gles(2). 



Other species, generally less oblong and slightly inclined before, 



in which the mandibles are always moderate or project but little in 



both sexes, with the thorax strongly dentated laterally; where the 



antennae are pectinated or strongly serrated in the males, and com- 



(1) See Fab., Oliv., Lat., Gyll., &c, &c. 



(2) The Prioni giganteus, cervicornis, damrcornis, maxillosus, barbatus, faber, 

 serripes, &c, of Fabricius and Olivier. 



