200 COLEOPTERA OP NORTH AMERICA. 



Prothorax small, quadrate, lateral margin well denned, 

 side pieces not separate; prosternum entire, with a slight 

 pointbehind fitting into themesosternum; coxal cavitiessmall, 

 transverse, open behind ; under surface excavated for the 

 reception of the anterior legs. 



Mesosternum large, quadrate, receiving in front the ex- 

 tremity of the prosternum ; side pieces excavated for the 

 middle legs, and attaining the coxae. 



Metasternum moderate, side pieces narrow, epimera not 

 visible. 



Elytra entire, with rows of large square punctures, and in- 

 termediate ribs; epipleurae narrow, extending to the apex. 



Abdomen with five free ventral segments. 



Anterior coxae small, not prominent, slightly separated ; 

 middle coxae quadrate, flat, contiguous; posterior transverse, 

 flat, sulcate posteriorly, receiving the thighs in repose. 



Legs slender, contractile ; tibiae without terminal spurs ; 

 tarsi 5-jointed, slightly dilated, spongy beneath ; claws small, 

 simple. 



A family containing a single very anomalous genus, of which 

 but two species inhabit the United States ; one of them, G. capi- 

 tata, is black, with the head red ; the other, C. cinerea, is pale 

 gray, with darker lines. They are found under bark of decaying 

 trees, and also occasionally in houses. 



The affinities of this family are very obscure ; in the form and 

 insertion of the antennae it is similar to the first genera of the 

 next family, but other characters, such as the form of coxas and 

 retractility of the legs, are at variance. The body is covered 

 with small scales as in the genera alluded to. 



In this condition of doubt, I leave the family where it was placed 

 by Lacordaire. 



Fam. xlv.— ptinidae. 



Mentum usually small and quadrate, sometimes larger and 

 transverse, corneous; ligula membranous or coriaceous, with- 

 out paraglossia; palpi 3-jointed, short. 



Maxillae exposed at base, with two ciliate lobes, the in- 

 ternal one sometimes very small; palpi 4-jointed, short. 



Antennae inserted upon the front in the first sub family, 

 at the sides of the front in the others, having from 9 — 11 

 joints, variable in form. 



