TBV. OABRIOX BEETLKS. 273 



fforw.— "Synopsis of the Silphidaa of the United States with 

 reference to the Genera of other (!onntries," in Trans. Amer. 

 Ent. Sof.. VIII, 188n. 219-322. 



Nearly 900 species of Silphida? are known, about 125 of which, 

 distributed amont;- 31 genera, are from North America. Horn, in 

 his Synopsis, divided the family among six tribes. Four of these 

 are known to be represented in Indiana, while a single species of an- 

 other may occur. 



KEY TO INDIANA TKIBES OF SII,PHID.5!;. 



11. Hind coxEB simple. 



/*. Front coxse more or less transverse at base and witti trocliantin. 

 c. Front coxal cavities open behind. 



fl. Hind coxoe contiguous; larger, 10 or more mm. 



Tribe I. Silphini, p. 273. 

 I.U1. Hind coxae separated ; eyes wanting ; smaller, not over 2 mm. 



Tribe II. Pinodytini, p. 277. 

 cc. Front coxal cavities closed behind ; length less than ."i mm. 



Tribe IV. Anisotomini, p. 2S4. 



hi). Front cox;c cylindric-conic, without trochantin. the cavities closed 



behind; length less than 6 mm. Tribe III. Cholevini, p. 278. 



00. Hind coxse with laminije or plates ; size very small, not over 2 mm. 



Tribe V. Clambini, p. 291. 



Tribe I. SILPHINI. 



To this tribe belong all the larger members of the family, the 

 distinctive characters being the open front coxal cavities and the 

 contiguous hind coxa?. The form is sometimes elongate, but usually 

 oval or even nearly circular : elytra distinctly, sometimes widely. 

 margined at the sides ; abdomen often visible beyond the elytra. Of 

 the seven genera comprising the tribe, three are represented in In- 

 diana. 



KEY TO INDIANA GENEBA OF SILPHINI. 



a. Antennse ten-jointed, the last four joints forming an abrupt club ; mid- 

 dle coxae widely separated. I. Necrophorus. 

 aa. Antennte eleven-jointed, either slender or gradually clavate. 



6. Middle coxse moderately separated; front coxal cavities widely open 

 behind; elytral sti-ire, if present, not punctured. II. Sit.pha. 



66. Middle cox;e narro-wly separated or contiguous ; front coxal cavities 

 narrowly open; elytral strias with distinct impressed punctures. 



III. Necrophii.ts. 



1. XECBOPHORfs Fab. 177:". (Or., "a dead body i bearing.") 

 To this genus belong large, elongate, thick-bodied beetles, having 



