SILPHIDAE. 41) 



elytra, and the widely separated posterior coxae. Like nearly all 

 cave insects, it is destitute of eyes. Doubtless, species of this 

 genus remain to reward the scientific explorers of our large west- 

 ern caves. 



According to the form of the body, and the position of the 

 posterior trochanters, the following tribes are defined : — 



Posterior coxas simple ; 



Posterior trochanters prominent (body not globose). Silphini. 



Posterior trochanters not prominent (body nearly globose). 



Anisotomim. 

 Posterior coxae laminate, covering the legs. Clambini. 



Tribe I.— SILPHINI. 



Body never globose, sometimes elongate, usually oval, or even 

 nearly circular, and then usually with a thin margin of the thorax 

 and elytra extending beyond the body ; the antenna? are 11-jointed, 

 but with the second joint in one genus (Xecrophorus) almost obso- 

 lete ; with a globose 4-jointed club in that genus, gradually clubbed 

 in the others, with the eighth joint in some genera smaller than 

 the contiguous ones. Epimera of metathorax not covered by the 

 elytra. Posterior coxa? contiguous, or nearly so ; their trochanters 

 prominent internally, frequently emarginate or toothed. Tarsi 

 5-jointed, except in the female of Adelops, where the anterior 

 ones are only 4-jointed. 



This sub-family contains the largest insects of the family ; the 

 species of Necrophorus are remarkable for the black elytra, trun- 

 cate at tip, and ornamented with large red spots. They live on 

 dead animals, and a pair of them will bury the body of a small 

 mammal with wonderful rapidity. Silpha is also easily recog- 

 nized by the rounded outline and thin margin. 



Our genera may be thus arranged, in two sub-tribes : — 



Abdomen with six visible ventral segments. Silphini. 



Abdomen with five visible ventral segments. Sph^ekitiui. 



Sub-Tribe 1. — Silphini (genuini). 



Nothing general can be stated in regard to the genera of this 

 sub-tribe ; which may be divided, according to the position of the 

 head, into two groups. 

 4 



