90 GEO. H. HORN, M. D. 



The thoracic ridges are here still less distinct than in californieus. 

 The elytral sculpture is, however, similar, excej^t that in sonatus the 

 striiB are less deep, ■svhile the granules of the intervals are nearly 

 equal. The clypeus on each side of the emargination is nearly as 

 distinctly angulate as in Aphodius serval, by which means this and 

 the next species may be readily separated from the others. 



Occurs in Kansas, Colorado and Montana. 



RIi. riparius Horn. — Brownish black, oblong, moderately convex, oj>aque, 

 legs brown. Anteunse pale. Head moderately convex, closely and relatively 

 coarsely granulate, vertex with elevated arcuate line interrupted at middle, 

 sometimes in form of chevron. Clypeus broadly emarginate at middle, on each 

 side distinctly angulate. sides oblique, feebly arcuate, gense obtuse. Thorax one- 

 fourth wider than long, anterior angles obtuse, sides irregularly arcuate, margin 

 crenate, hind angles broadly rounded, base arcuate, the marginal line indistinct, 

 disc convex, rather coarsely granulate, witli four indistinct, transverse discal 

 ridges, the first only entire, a very distinct, broad, median sulcus from the first 

 carina to base. Elytra as wide as the thorax, humeri slightly dentate, disc in- 

 distinctly striate, intervals with two rows of small tubercles, the inner scarcely 

 evident, the outer distinct, each tubercle with a short yellow scale-like hair. 

 Mesosternum opaque, densely punctured, a very fine and short median carina. 

 Metasternum scabrous at sides. Abdomen sparsely punctate, each puncture with 

 a scale like hair, the segments crenate in front. Posterior femora sparsely punc- 

 tate with scale-like hairs, the marginal line distinct, first joint of hind tarsi 

 nearly as long as the next three. Length .12-.14 inch ; 3-3.5 mm. 



In this species the granules of the head and thorax are relatively 

 coarser than in any of our species. The transverse ridges of the 

 thorax are very feebly indicated, in fact the ridges are so broad that 

 the narrow grooves separating them seem the feature of the sculp- 

 ture. In my original description the grooves are spoken of to the 

 exclusion of the ridges, but for the sake of uniformity and greater 

 ease in comparison the same method of description has been adopted 

 for all the species. 



With this species I have united ccdatus Lee. On comparing the 

 types I find them identical in every respect. At the time of the de- 

 scription of ccekdus, riparim was represented by an unique specimen 

 and Dr. LeConte had no specimen at hand for comparison. 



Occurs in Ai'izoua from Cam]) Grant southward. 



PLiEUROPHORUS Muls. 

 This genus does not seem to have been admitted by the greater 

 number of authors who have had occasion to deal with it since first 

 suggested by Mulsant. The characters are rather feeble, but seem 

 to possess fully as much value as those allowed to separate other 

 genera in the group. 



