394 COLEOPTERA OF NORTH AMERICA. 



Elytra rounded behind, covering the abdomen; epipleurre 

 not very wide, extending to tlie apex. 



Abdomen with five free segments; the first elongated, tlie 

 5tli marked with a curved submarginal I'urrow in our genus. 



Legs moderate, strongly contractile; anterior coxas dis- 

 tant, scarcely visible, rounded ; middle coxae flat, widely 

 separated ; hind ones flat, transverse, widely separated; mid- 

 dle thighs suddenly contracted at the base; tibise slender, 

 compressed ; tarsi not dilated, slightly pubescent beneath ; 

 anterior and middle ones 5-jointed, hind ones -i-jointed ; 

 claws small, simple; first joint of hind tarsi long. 



This family consists of small, black, oval flattened insects, re- 

 sembling in appearance Triplax of the Erotylidae. It appears 

 to constitute a very distinct type, without well-marked affinities 

 with any other family. It contains but two genera: Monomma 

 conlined to the Eastern, Hyporhagus to the Western Continent. 

 Of the latter genus one species is found in the Atlantic, and three 

 in the Pacific district. 



Fam. LXIV.— melandryidae. 



Mentum transverse, trapezoidal, generally narrower in 

 front, supported on a large gular process; ligula prominent; 

 labial palpi 3-jointed. 



Maxillae with two flattened ciliate lobes; palpi 4-jointed, 

 frequently very long and much dilated. 



Head usually deflexed, generally not constricted behind ; 

 received into the thorax not as far as the eyes; suddenly 

 constricted behind in Scraptia ; eyes emarginate or entire, 

 and not finely granulated; clypeus often subcoriaceous ; 

 labrum prominent; mandibles short. 



Antenme 11-jointed in our genera (10-jointed in the 

 foreign genus Conopalpus); generally filiform ; sometimes 

 thicker externally, inserte'd under very small oblique frontal 

 ridges. 



Prothorax as wide behind as the base of the elytra (except 

 in Stenotrachelini and Mycterini), with the lateral suture 

 nearly always distinct; anterior coxal cavities open behind, 

 frequently confluent. 



Mesosternum moderately long, side pieces attaining the 

 coxal cavities; metasternum long, side pieces narrow; epi- 

 mera visible. 



