338 COLEOPTERA OF NORTH AMERICA. 



wider than the head, of varied form, not margined. Elytra wider 

 than the prothorax, strongly punctured, margined, entire, epi- 

 pleuros narrow, but distinct. Front coxae conical, transverse, 

 prominent, and contiguous, or not prominent and narrowly sepa- 

 rated ; middle and hind coxse narrowly separated. Legs mode- 

 rate, tibiffi without spurs, tarsi dilated, claws variable. First 

 ventral segment as long or nearly so, as the two following united. 

 Two groups are indicated by our four genera: — 



I. Front coxae not prominent, separated ; coxal cavities closed. 



Orsodacn^b. 



Prothorax somewhat bell-shaped. Orsodacna. 



II. Front coxse prominent, contiguous. Synet^b. 



Prothorax with a lateral tubercle ; eyes emarginate ; front coxal 



cavities closed ; claws appendiculate. Zeugophora. 



Pi-othorax toothed at the sides ; eyes entire ; front coxal cavities 



open ; claws cleft. Syneta. 



Prothorax subangulated at the sides, with prominent front and hind 



angles ; eyes entire ; front coxal cavities open ; claws entire, 



divergent. Thricolema. 



Thricolema has one species in California ; the other three 

 genera are widely distributed. 



The second group might be equally well placed in the following 

 tribe, but in so restricted a fauna as that here investigated, it is 

 really of but little importance, so long as the characters of the 

 group are made distinct, in which of the larger divisions it is 

 placed. 



Tribe III.— CRIOCERI\I. 



This tribe contains species of rather small size and graceful 

 form ; the prothorax is narrower than the elytra, not margined 

 on the sides, and is usually mai-ked with a strong transverse con- 

 striction behind the middle. The elytra are regularly punctato- 

 striate, and cover the dorsal segments completely; the epipleurse 

 are not distinctly defined. The head is somewhat constricted 

 behind, the front forms a broad and short muzzle; the eyes are 

 pi-ominent and rounded; the antennas are widely distant, inserted 

 in front of the eyes, 11 -jointed, and rather stout, though not 

 thicker externally. The frojit coxae are conical, prominent, and 

 nearly contiguous; and the cavities ore closed behind. The 

 middle and hind coxae are moderately separated ; the 1st ventral 

 segment as long as the two following. The legs are short, not 



