314 COLEOPTERA OP NORTH AMERICA. 



more extended observation, the group as here denned contains 

 all those genera in our fauna in which the eyes are finely granu- 

 lated, deeply emarginate, with the upper lobe wide; the scutellum 

 acute, but not very large, though sometimes elongate ; and the 

 prothorax not distinctly lobed, but only feebly bisinuate or trun- 

 cate at base. The antennae are more slender than in Trachyderes, 

 and the poriferous system is much less distinct, or even obsolete, 

 though in Stenaspis it is still quite obvious, and the joints are 

 carinate and bisulcate. In Batyle the last joint of the palpi 

 (which is subcylindrical, and truncate) is very feebly impressed. 



The antennal tubercles are either much elevated, leaving a 

 concavity between them, or scarcely elevated, in which case the 

 vertex is neaiiy flat ; the front in the former is very large, square, 

 and perpendicular, and the genae are long ; in the latter the tuber- 

 cles are less elevated, the front is moderate, declivous, and the 

 genas usually short. 



They may be thus tabulated : — 



A. Front large, square, perpendicular, abruptly separated from the ante- 



ocular spaces ; 

 Prothorax bituberculate at the sides, body glabrous ; 



Mesosternurn protuberant. Stenaspis. 



Prothorax armed with a lateral spine ; mesosternurn not protuberant ; 



Body pubescent. Tragidion. 



Body glabrous. Purpuricenus. 



Prothorax rounded, convex. Aethecert/s. 



B. Front moderate, short, declivous, not abruptly defined each side ; 



Two ivory vittse on each elytron ; 



Mesosternurn declivous ; (prothorax margined at apex). 



Mannophorus. 

 One ivory vitta on each elytron ; 

 Mesosternurn protuberant ; (prothorax not margined at apex). 



Entomostehna. 

 Elytra without ivory vittae ; mesosternurn declivous ; 



Body pubescent, prothorax not margined at apex. Amannus. 

 Body pilose, prothorax margined at apex. Batyle. 



Of the three species of Tragidion, two have the elytra sulcate, 

 while T. armatum has them even : there is also a difference in 

 the hind tarsi, which are comparatively wider in T. annulatum. 

 Variations in the proportions of the joints of the hind tarsi are 

 not unusual in Cerambycidae, as, for instance, in Criocephalus. 

 This fact has induced me to refer Sphsenothecus cyanicollis to 



