Horn.] Ol-J [June 20, 



Antennal cavities at the sides of the prosternum. An- 

 tennas inserted under the frontal margin Saprinus. 



Antennal cavities on the under side of prothorax in front 

 of the coxae. Antenna? frontal. 

 Eyes finely granulated, not prominent. 

 Thorax without deep lateral groove. 



Tibiae toothed. Pygidium regularly convex Teretrius. 



Tibia; spinulo.se. Pygidium double Teretriosoma. 



Thorax with deep lateral groove. Prosternum deeply 



bisulcate, body oblong. Tibia; not toothed Plegaderus. 



Eyes coarsely granulated and very convex. 



Hind tarsi live-jointed. Scutellum invisible Bacanius. 



Hind tarsi four-jointed. 



Scutellum distinct Acritus. 



Scutellum invisible Aeletes. 



Bacanius has been removed from the preceding sub-tribe and placed 

 near Acritus with which it appears to have many points of resemblance. 

 The eyes of the last three genera are rounder and more convex than is 

 usual in the entire family and very coarsely granulated. The >scape of 

 the antenna; is lodged in a deep groove immediately in front of the eyes, 

 which are not bordered by a narrow corneous band in front. The deep 

 groove adds still further to the apparent convexity of the eyes. 

 Saprinus, Leach. 

 The arrangement of the species of this genus in groups, adopted by 

 Dr. Leconte (Proc. Acad. VI., p. 40), appears to afford the most natural 

 method of their subdivision and is, at the same time founded on charac- 

 ters which are much the least variable of any that can be made use of. 

 "With some slight modification to avoid the use of the epipleural striae, 

 the following system is identical, and the groups here retained are 

 equivalent to those already established. 

 Front not margined. 



Hind tibia; more slender than the middle tibia' and at apex 

 narrower than at middle, outer edge and apex not spinu- 



lose Group, i. 



Hind tibiae as broad or broader than the middle, at apex 

 always broader, outer edge spinulose. 

 Prosternum flat, striae horizontal and united in front. . . . Group, n. 

 Prosternum at least moderately convex. 



Prosternum without striae Group, ill. 



Prosternum distinctly striate. 



Stria; parallel, horizontal, abbreviated in front....... Group, iv. 



Striae divergent and ascending. 

 Prosternum moderately convex. 



Prosternum anteriorly not foveate , Group, v. 



Prosternum foveate Group, vi. 



Prosternum compresso-carinate Group, vu. 



