Horn.] —0\) [June 20, 



be added. Between the punctures, however, the stria?, 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. Epi pleurae 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 scaber of Southern 

 Europe. The two differ primarily in the surface sculpture particularly 

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

 figures of the two. The outer marginal stria? of the thorax do not exist 

 i:i guttifer, two are said to exist in scaber, of which *ho'wever 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 epipleura? 

 are punctured and not striate in the former and very distinctly unistriate 

 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 stria? and occasionally with the evi- 

 dences of a third. Hind tibia? narrower at base than at apex and 

 biseriately spinulose and rarely with the spiuules somewhat confused, 

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

 striate. Tarsal groove of anterior tibiae badly defined. 



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

 of species which for convenience may be divided into groups. 

 Margin of thorax ciliate, Autennal cavities shallow. 

 Outer marginal thoracic stria entire, anterior tibia? 



dentate Gr. arcuutus. 



Outer marginal stria abbreviated, anterior tibia? not 



dentate Gr. laevipes. 



Margin of thorax not ciliate, Autennal cavities deep. 

 Mesosternum emarginate. 

 Subhumeral stria entire. 

 Elytra 3-striate ; outer thoracic stria very close to 



margin Gr. sexstriatus. 



Elytra 4-striate ; outer thoracic stria often absent 

 or when present distant from margin. 



( luter thoracic stria entire Gr. merdariuS' 



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

 ihumeral stria interrupted, often entirely obsolete. 



Tibiae serrulate Gr. abbreviates. 



Tibia? tridentate Gr. depurator. 



Mesosternum truncate (Atholus, Thorns.) 



Epipleura? very narrow, unistriate Gr. bimaeulatus. 



Epipleura? bistriate and broader Gr. arm ricanus. 



