436 COLEOPTERA OF NORTH AMERICA. 



Tribe I— BRACHYDERIIVI. 



Rostrum at least as long as the head and slightly dilated at 

 tip, which is more or less eraarginate. Front flat, rarely with a 

 slight depression between the eyes. Scrobes moderately deep, 

 usually distinctly limited and very oblique. Antenna? moderate, 

 !^cape attaining the eyes rarely (Trigonoscnta) passing them. 

 Thorax without ocular lobes or fimbria? and not or very feebly 

 emarginate beneath. iScutellum usually distinct. Elytra oval, 

 not wider than the thorax. Mesosternal epimeron small, epi- 

 sternum attaining the elytra. Episternum of metasternum narrow, 

 suture usually distinct in its. entire length. Abdomen with the 

 first two segments (except in Gr. iv.), separated by an arcuate 

 suture, segments 3-4 short, conjointly not or but little longer than 

 the second. 



As thus constituted, the tribe is widely different from that 

 defined by Lacordaire under the same name. From it those 

 genera have been removed in which the mesosternal side pieces 

 are diagonally divided and the metasternal episterna moderately 

 wide and dilated in front. These form tribes in the next division. 

 It is, however, extremely difficult to fix tribal limits with any 

 degree of certainty, as every character upon which classification 

 has been based, exhibits a degree of variability almost unparal- 

 leled in any other series of Coleoptera. The ocular lobes of the 

 thorax especially exhibit this tendency, and the pointed outline 

 of the eye which usually accompanies the lobe is by no- means in 

 better condition. The eye may be more nearly circular in outline 

 with a lobe than it is without the lobe. 



As thus constituted, the tribe contains the following groups: — 



Third joint of all the tai'si wider than the second and deeply bilobed ; 

 Tibiae normal, not dilated at tip ; scape not passing tlie eyes ; 



Posterior coxae small, very widely separated. MiNYOMEKr. 



Posterior coxra normal, intercoxal process triangular or oval ; 

 Antennae scaly, body beneath densely scaly ; elytra emarginate at 

 base, thorax closely applied. Epic^ri. 



Antennae shining, sparsely hairy, body beneath nearly naked ; 



Tips of hind tibiae feebly cavernous, a double row of spinules ; first 

 ventral suture- arcuate. Barynoti. 



Tips of hind tibi;e open, a single row of spinules ; 



First ventral suture straightior nearly so ; claws free. Hormori. 

 First ventral suture sinuous ; claws connate. Bkachydekks, 



