158 COLEOPTERA OF NORTH AMERICA. 



This family contains Derodontus, represented by two species; 

 Cryptophagus inaculatus Mels., from tlie Atlantic district, and 

 Corticaria ir-isignata Mann., from Russian America; and Pel- 

 tastica Mann., from Alaska and Oregon. 



Protliorax naiTower than elytra, strongly toothed on the sides. 



Derodontus. 

 Body oval, margin broadly flattened and reflexed. Peltastica. 



The- form of the anterior and posterior coxae distinguishes this 

 from all the preceding families, and approximates it somewhat to 

 the families following the Elaterida^. 



The species of Derodontus are small, testaceous, or brown, 

 coarsely punctured insects, having the head deeply impressed, 

 with a small smooth tubercle each side inside of the eye, which 

 at first sight resembles a large ocellus. The thorax is compara- 

 tively small, channelled, and its lateral margin is strongly toothed; 

 the elytra are wider than the thorax, with strice composed of 

 large punctures, and are variegated with darker spots. Peltas- 

 tica resembles in miniature Peltis; the color is pale, and the 

 elytra are ornamented with several rows of polished dark spots. 



Fam. XXXY.— byrrhidae. 



Mentum transverse (except in JSTosodenclron), corneous; 

 ligula usually prominent, simple. 



Maxillae exposed at base, with two unarmed lobes. 



Antenna rarely 10-, usually 11-jointed, the outer joints 

 forming an elongate club in most genera, nearly filiform in 

 Amphicyrta. 



He^ad prominent in Nosodendron, retracted in the other 

 genera, with the parts of the mouth more or less protected 

 by the prosternurn ; epistoma usually wanting, sometimes 

 short, coriaceous, sometimes corneous ; labrum distinct ; 

 mandibles short, not prominent. 



Protliorax with- the side pieces not separate; coxal cavi- 

 ties large, transve-rse, open behind, separated by the pro- 

 sternum, which is short, truncate in front, slightly prolonged 

 behind, fitting into the mesosternum. 



Mesosternum small, prominent, emarginate, or excavated; 

 side pieces largely attaining the coxfe. 



Metasternum short, broad; side pieces narrow; epimera 

 not visible. 



