18 PROCEEDINGS OF THE NATIONAL MUSEUM vol. lu 



Onthophagus cochisus Brown 



Plate 2, Figures 9 and 10 



Onthophagus cochisvs Brown, 1927, p. 132. — Boucomont, 1932, p. 317— Leng 

 and Mutchler, 1933, p. 38. 



Male majors. — Length 8.5 to 9.8 mm., width 5.3 to 6.2 mm., color 

 black. Head with clypeus reflexed anteriorly, the disc appearing 

 slightly concave; margin anteriorly broadly arcuate, laterally sharply 

 angulate with sides almost parallel; disc coarsely punctate, punctures 

 becoming more crowded laterally and posteriorly; clypeal carina 

 obsolete, indicated only by a slight convexity medially between the 

 clypeus and frons. Frons coarsely and densely punctate as is the 

 gena; carina of vertex low, bowed anteriorly, ending shortly behind 

 each eye in a slightly elevated sharp ridge. Vertex coarsely 

 punctate for a short distance behind the carina, the surface then 

 becoming smoothly alutaceous. Genae with lateral margins extending 

 a short distance beyond the lateral margins of the clypeus, but 

 with the sides only slightly arcuate, nearly parallel. 



Pronotum completely margined, poorly so posteriorly; anterior 

 angles almost forming right angles; lateral pronotal margin bent 

 abruptly upward approximately 1 mm. behind the anterior angles, 

 forming a sharp, nearly tuberculate angulation. Pronotum widest 

 at the middle, approximately 1 mm. behind the angulation, convex, 

 similar in shape to the related Mexican species 0. chevrolati Harold; 

 the anterior tumosity rising almost perpendicularly behind the anterior 

 margin, with face of the tumosity broadly rounded and laterally con- 

 cavely arcuate to the small lateral tubercles. Surface of the pronotum 

 smoothly, shallowly concave between the tumosity, tubercles, mar- 

 ginal angulations, and anterior angles; discal surface of pronotum 

 coarsely, densely punctate; anteriorly the surface of the tumosity 

 shining, with the punctures large and often bearing short setae; 

 posteriorly the surface between the punctures dull and alutaceous, 

 with the punctures smaller and bearing short but distinct setae. 

 Elytral striae punctate, scarcely impressed; intervals, except for 

 sutural interval, with from three to five irregular rows of small shiny 

 tubercles, each with a short black seta at its base; surface alutaceous 

 between the tubercles. 



Pygidium alutaceous except for smooth apex, the entire surface 

 with scattered shallow punctures, each with a short seta. Ventral 

 surfaces of thorax shining, laterally coarsely punctuate, most of the 

 punctures bearing long fine reddish setae; metasternum fin el}'" punc- 

 tate along the shallowly impressed median line; abdominal segments 

 finely alutaceous, laterally spai-sely punctate; last segment piceous in 

 color, narrowed medially, emarginate to receive the pygidium. Fore- 



