Horn.] ^0\J [June 20, 



be added. Between the pimctiires, however, the stride, in a partially 

 obliterated condition appear, and at the sides an almost entire subhume- 

 ral appears. Thorax without external marginal stria, inner stria nearly 

 obliterated and very distant from the margin. Epipleiira3 of elytra 

 unistrate. Length .18-.20 inch ; 4.5-5 mm. 



Occurs along the eastern base of the Rocky Mountains, from Nebraska 

 to Texas. 



The only other species of the sub-genus is the scubcr of Southern 

 Europe. The two difter primarily in the surface sculpture particulai'ly 

 that of the thorax, and which can be best seen by a comparison of the 

 figures of the tvro. Tlie outer marginal stri?e of the thorax do not exist 

 in guttifei; two are said to exist in scaler, of which however one only is 

 at all distinct. The subhumeral stria is nearly obliterated in scaber and 

 almost entire and very distinctly impressed in our own. The epipleurfe 

 are punctured and not striate in the former and very distinctly unisti'iate 

 in the latter. The under surface of the body is coarsely punctured in 

 the former and nearly smooth at middle in the latter, and the femora of 

 of each species partake of the sculpture of the under surface. Both 

 species are broadly oval. 



Sub-genus Hister, 

 Thorax with two lateral marginal strise and occasionally with the evi- 

 dences of a third. Hind tibite narrow^er at base than at apex and 

 biseriately spinulose and rarely with the spinules somewhat confused, 

 anterior tibiae variable, either bi-, tri- or multideutate. Elytra always 

 striate. Tarsal groove of anterior tibite badly defined. 



The sub-genfts Hister as above restricted contains a very large number 

 of species which for convenience may be divided into groups. 

 Margin of thorax ciliate, Antennal cavities shallow. 

 Outer marginal thoracic stria entire, anterior tibire 



dentate Gr. arciiatus. 



Outer marginal stria abbreviated, anterior tibite not 



dentate Gr. laecipes. 



Margin of thorax not ciliate, Antennal cavities deep. 

 Mesosternum emarginate. 

 Subhumeral stria entire. 

 Elytra 3-striate ; outer thoracic stria very close to 



margin Gr. sexsfriatus. 



Elytra 4-striate ; outer thoracic stria often 'absent 

 or when present distant from margin. 



Outer thoracic stria entire Gr. merchirius- 



Outer thoracic stria much abbreviated or absent. Gr. foedatus. 

 Subhumeral stria interrupted, often entirely obsolete. 



Tibias serrulate Gr. ahhreviatus. 



Tibiaj tridentate Gr. depurator. 



]\[esosternum truncate (Atholus, Thorns.) 



Epipleuraj very narrow, uuistriate Gr. bimaculatus. 



Epipleurse bistriate and broader Gr. amerieanus. 



