BEETLE GENUS ONTHOPHAGUS — HOWDEN, CARTWRIGHT 101 



wider aud more convex, being 10 facets wide with a ratio of width to 

 length 7 to 10; in velutinus the ratio is 5 to 11, the width 7 facets; in 

 hrowni 4 to 10 ratio, 6 to 7 facets width. 



The male major pronotal protuberance is rather similar to that of 

 0. medorensis. 



Nothing is known about the habits of arnetti, the three specimens 

 having been taken at light. However, one might do well to look for 

 arnetti in wood rat nests, inasmuch as it is similar to hrowni and velu- 

 tinus, both of which occur in Neotoma nests. 



We take pleasure in naming this species after its first collector, 

 Dr. Ross H, Arnett, Jr., founder and for many years publisher of 

 the Coleopterists' Bulletin. 



Onthophagus hrowni, new species 



Plate 7, Figures 66 and 67 



HoLOTYPE. — Male major, length 6.6 mm., width 3.7 mm. Dorsal 

 surfaces dull black, finely alutaceous between the pronotal tubercles 

 and elytral striae, in these respects being similar to 0. velutinus. 

 Clypeus reflexed anteriorly and broadly, very shallowly emarginate; 

 disc coarsely, rugosely punctate, delimited posteriorly by a small but 

 distinct, sHghtly sinuate carina rmming from margin to margin. 

 Frons, vertex, and gena alutaceous and having scattered coarse punc- 

 tm-es which often bear mmute reddish setae; carina on vertex indis- 

 tinct medially, forming a pronounced ridge behind each eye but 

 without any indication of a horn; gena flared laterally by the front of 

 the eye, more noticeably arcuate than in velutinus. 



Pronotum margined anteriorly and laterally, dorsal surface moder- 

 ately tuberculate, each tubercle overhanging a small puncture bearing 

 a minute reddish seta, tubercles separated by a distance equal to 

 three or more times their diameter, more crowded anteriorly on the 

 pronotal protuberance; pronotal protuberance flattened, projectmg 

 forward as an inverted triangle one-third wider anteriorly than at its 

 base, the strongly sinuate anterior margin broadly shallowly emargi- 

 nate at middle and curving laterally more sharply posteriorly to the 

 outer angles. A large, deep, smooth, impunctate fossa beneath the 

 protuberance on each side; anterior angles abruptly rounded, lateral 

 margins arcuate, slightly sinuate anteriorly, with a small knob above 

 each margin near the middle. The elytra with smooth, shining, narrow 

 striae; all except sutural interval irregularly, biseriately tuberculate; 

 behind each tubercle a minute puncture bearing a short reddish-yellow 

 seta; surface between tubercles alutaceous. Except for the deeper 

 strial punctures, the elytra almost identical to those of velutinus. 



Pygidium coarsely punctate, dull and noticeably alutaceous basally, 

 becoming shiny and smooth apically. Ventral surfaces brownish black 



