454 BULLETIN UNITED STATES GEOLOGICAL SURVEY. 



emarginate iu front, with acute promineut angles, sides oblique, edge 

 reflexed, genae prominent subacute. Prothorax one-half wider than long, 

 sides parallel, finely margined, anterior and posterior angles rounded, 

 base very finely margined; surface sparsely finely punctured, punctures 

 more numerous at the sides. Elytral striae punctured, interspaces very 

 slightly convex, scarcely visibly sparsely punctulate. Mesosternum not 

 cariuate, opake, finely alutaceous, with a very faintly impressed median 

 line in front. Spinules of hind tibise very short, equal. Length G.8™°^ 

 (0.27 incli). Colorado. One specimen, in Dr. Horn's collection. 



15. Aphodius duplex, n. sp. 



Subcylindrical, piceous black, shining. Head convex, tuberculate, 

 finely punctured, epistome rugose, broadly subemarginate in front, 

 sides finely margined, gense rounded, not prominent; the three tu- 

 bercles of the vertex are rounded, the frontal one is replaced by a 

 narrow transverse ridge parallel with the anterior margin of the epi- 

 stome. Prothorax about twice as wide as long, narrower in front, sides 

 and angles rounded, finely margined; base equally finely margined; 

 surface finely, not densely, punctured, with large punctures sparsely 

 intermixed; sides yellowish towards the front angles. Scutellum very 

 sparsely punctulate. Elytral strise deep-punctured, interspaces slightly 

 convex, very finely and sparsely punctulate. Mesosternum alutaceous 

 opake, very finely channelled in front. Spinules of hind tibiae short, 

 equal. Antennae and legs brown. Length 4.1™™ (0.16 inch). 



Colorado, Dr. Horn. Similar in form and size to A. granarius, but 

 quite different by the head from any species known in our fauna. 



16. Aphodius obtusus, n. sp. 



Elongate, cylindrical, piceous; sides of prothorax, antennae, palpi, 

 legs, and elytra dull yellow. Head not tuberculate, sparsely punctu- 

 late ; epistoma obtusely rounded and subtruncate in front, without 

 prominent angles ; sides oblique, flattened, rugose, genae moderately 

 prominent, rounded at tip. Prothorax wider than long, sides finely 

 margined, feebly rounded, hind angles very much rounded ; base finely 

 margined ; surface not densely, nor coarsely, but moderatelj^ and 

 equably punctured, gradually paler towards the sides. Scutellum flat, 

 smooth. Elytra with rather strongly punctured striae ; interspaces 

 slightly convex, sparsely punctulate. Mesosternum opake, densely 

 punctured in front, finely alutaceous behind, with a slender but well- 

 defined impressed median line extending from the coxae as far as the 

 punctured part. Spinules of hind tibiae equal, short. Length 6""" 

 (0.25 inch). 



Colorado (locality unknown); one specimen, in Dr. Horn's collection. 

 This very distinct species belongs to a separate group after G, of Dr. 

 Horn's revision (Trans. Am. Ent. Soc. 1870, 110). It is easily recog- 

 nized by the finely channelled mesosternum. 



