378 COLEOPTERA OF NORTH AMERICA. 



slender, and the tibial spurs are more conspicuous than in the 

 other two groups, the tarsi are clothed beneath with a rigid 

 pubescence ; the epipleurge are variable in length. The mentum 

 is flat and trapezoidal. 

 Our genera are : — 



Antennse gradually thicker toward the tip, palpi and tarsi short ; 



Epipleurse entire. Tenebrio. 



Epipleurse abbreviat(!d ; 



Head subqnadrate, similar in the sexes. Bius. 



Head transverse, dissimilar in tlie sexes. Adelina. 



Autennje elongate, slender ; palpi long, tarsi sleiider ; 



Mentum emarginate in front. Alaephus. 



Mentum truncate in front. Eupsophus. 



The last two genera are peculiar to the Pacific region, the 

 others are widely distributed. Adelina contains two species of 

 very depressed form and testaceous color ; since the preceding 

 edition they have been placed in SitojjJiagus Muls., which is now 

 known to be a synonym of Ulosonia. 



Tribe v.— PEDI^I^I. 



Body oval, not very convex; epistoma emarginate, covering 

 the base of the mandibles; labrum prominent; mentum frequently 

 trilobed in front, small or moderate in size ; gular peduncle 

 distinct; ligula prominent, entire or slightly sinuate in front; 

 eyes transverse, sometimes divided ; elytra embracing feebly the 

 flanks of the abdomen; epipleurae narrow; anterior coxae sub- 

 transverse; middle coxae with distinct trocliantin, side pieces of 

 mesothorax extending to the coxal cavities; metasternum very 

 short, epimera distinct; hind coxse distant; intercoxal process 

 of abdomen truncate; tibial spurs small, distinct ; anterior, and 

 sometimes the middle tarsi of the male dilated, and spongy be- 

 neath; hind tarsi sometimes pubescent, sometimes spinous. 



Two groups occur in our fauna: — 



Eyes not divided. Platynoti. 



Eyes completely divided. Blapstini. 



Group I. — Platynoti. 



This group, distinguished by the epistoma being emarginate, 

 and the eyes not entirely divided, is represented in- our fauna by 

 only a few species of Opatrinus from the Atlantic district. Opa- 



