3TC COLEOPTERA OF NORTH AMERICA. 



These genera oceur in California and Arizona. The males of 

 Oratidus have a distinct tooth on the inner side of the posterior 

 tibia near the tip. 



The species of these genera are usually found walking on the 

 surface of the ground ; but AmpJridora littoralis lives in colonies 

 under oak bark. 



Tribe IV.— TEIVEBRIOIVIIVI. 



Bodv moderately elongated, apterous, or winged; head pro- 

 longed, but scarcely narrowed behind, not received in the thorax 

 as far as the eyes, which are transverse and emarginafe, mode- 

 rately finely granulated ; front dilated on the sides, covering the 

 base of the mandibles; epistoma truncate or slightly emarginate, 

 not separated from the labrum by a clypeus; antennte 11-jointed, 

 gradually thickened externally; mentum small, partly concealing 

 the ligula, inserted upon a galar peduncle; elytra embracing 

 feebly the flanks of the abdomen; epipleurte narrow. Anterior 

 coxte globose; middle coxa^ with distinct trochantin ;* legs long; 

 tibial spurs small; tarsi clothed beneath with silky, golden pubes- 

 cence, or with ordinary coarse pubescence. Hind margin of third 

 and fourth ventral segments subcoriaceous. 



This tribe embraces the Coelometopides of Lacordaire, with a 

 portion of his Tenebrionides; the vestiture of the tarsi appears 

 to be of more structural importance than the length of the raeta- 

 sternuiu, by whicii merely apterous and winged species are dis- 

 tinguished. The affinity pointed out between some of the genera 

 and the tribe Scaurini is very strong, and Polypleurus might be 

 equally well placed in the preceding tribe. 



The genera may be divided into two groups: — 



Tarsi silky pubescent beneath. Upes. 



Tarsi coarsely pubescent beneath. Tenebkiones. 



Group I. — Upes. 



In this group the hind coxte vary in position; the metasternum 

 in the apterous species is very short, but in the winged ones long; 

 the epipleurse do not reach the tip of the elytra in most of the 

 genera, and in othei'S they are gradually narrowed, reaching the 

 tip. 



The species are found under bark of dead trees. Our genera 

 are as follows : — • 



