H. C. FALL. 177 



interspace, and the faintest perceptible indications of the other 

 marking that usually accompany this ; in these there is also a 

 more or less evident pale median line on the prothorax. 



The type is one of a series of four specimens taken at 

 Deep Creek — 6500 feet — in the San Bernardino Mountains 

 in California. 



The affinities of the present species are with mixtus and 

 aureolus, and it may prove to be a variety of one or the other. 

 For the present, at least, mixtus may be separated by the 

 entirely black upper surface, and aureolus by the slightly 

 denser pubescence, which is always uniform in color through- 

 out ; in typical aureolus the legs are black. 



B. perplexus n. sp. 



Form not very robust, nearly as in aureolus ; black, the elytra pale 

 rufotestaceous with the tip of the humeral umbone and frequently the 

 base and more or less of the suture and side margins blackish ; legs 

 pale, the tarsi in great part, and sometimes the basal parts of the 

 femora blackish. Pubescence yellowish cinereous, rather dense, and 

 uniform throughout. Antenna? black, the basal four joints pale, outer 

 joints moderately transverse, scarcely serrate. Head finely sparsely 

 punctate and dull, front about equal in width to the eyes. Prothorax 

 a little wider than long, form and sculpture as in aureolus. Scutellum 

 oblong, a little elongate, emarginate apically. Elytra a little longer 

 than wide, gradually wider apically, finely striate, stria? not distinctly 

 punctate, intervals finely rugose-punctate. Pygidium moderately ob- 

 lique in the female, less so in the male, the latter with the first ventral 

 a little more pubescent at middle and with a very small basal rounded 

 feebly impressed fovea, which is more densely sculptured and pubes- 

 cent. Hind femora with a small acute tooth and one or two very 

 small denticles. Apical spur of hind tibia about one-fifth the length 

 of the first tarsal joint. Length lf-2^ mm. 



The type is from Alburquerque, New Mexico (Wickham). 

 With it are associated specimens from Highrolls, New Mexico, 

 Bright Angel, Arizona, Palm Springs, California, and Clare- 

 mont, California. 



This species is closely allied to aureohts and col/usus, dif- 

 fering from the former in scarcely any respect except color, 

 and from the latter by its black thorax, uniform pubescence, 

 and smaller size. Whether these differences are specific it 

 is quite impossible to say, but they may well be recognized 

 for the present by distinctive names. 



TRANS. AM. ENT. SOC, XXXVI. (23) JULY, 1910. 



