H. C. FALL. Ill 



This species is evidently very closely allied to Casey's 

 gentilis and gracilis, but differs from each in several details. 

 In gracilis the median groove of the pronotum is said to be 

 very wide, deep and conspicuous, the second joint of the 

 antennae much longer than the next two and the mentum not 

 impressed. In gentilis the size is somewhat greater, the 

 antennae are in great part black, the occipital fovea lacking, 

 the elytra relatively both wider and longer than in persimilis, 

 the hypomera only one-third as wide as their distance from 

 the coxae. 



B. mysticus n. sp. 



Rather robust, black, legs and basal two joints of antennae rufous. 

 Head and prothorax densely granulose and dull, elytra and abdomen 

 polished and strongly shining, the latter finely reticulate. Second 

 antennal joint nearly as long as the next two, tenth nearly twice as 

 wide as long. Head broadly convex, a transverse almost entire im- 

 pressed occipital line, which deepens into a foveiform impression at 

 middle ; epistomal suture fine, not impressed, punctuation fine, sparse, 

 shallow. Prothorax a little wider than the head, somewhat transverse, 

 sides broadly arcuate in front, the curvature continuous but stronger 

 posteriorly, hind angles rather abruptly formed, fairly well defined, 

 short, and but little obtuse; front angles a little obtuse and narrowly 

 rounded ; median line fine, lightly impressed, very slightly abbreviated 

 in front; punctuation rather fine, uniformly distributed, except as 

 usual along the median line, the punctures nearly twice their own 

 diameters apart. Elytra about as long as wide, fully one-third longer 

 than the prothorax, sides feebly divergent to apex, surface moderately 

 closely and strongly punctate. Abdomen finely very remotely punctate 

 above, a little less sparsely so beneath. Hypomera about two-fifths as 

 wide as their distance from the coxae, a little narrowed anteriorly, con- 

 cave posteriorly ; the prosternal sutures distinct ; coxal fissures long, 

 open, the surface immediately in front of them transversely impreseed. 

 Mentum broadly evenly concave, reticulate and shining. Length 3.6-4 

 mm. 



Washington (State) — type; Kalispell, Montana (Wick- 

 ham). 



This species belongs to LeConte's annularis group, and 

 judging from description is allied in a general way to sinu- 

 atns, which differs in color and is said to have the median 

 impressed line of the prothorax nearly obsolete. Monticola, 

 gentilis and gracilis of Casey are also related, but are all too 



TRANS. AM. ENT. SOC, XXXVI. MAY, 1910. 



