AMERICAN COLEOPTERA. 71 



punctured; prosternal inucro sliglitly flexed, raesosternutn not prominent. 

 Elytra moderately deeply striate, striae punctured, intervals convex, coarsely 

 punctulute. Body beneath and abdomen moderately coarsely punctate. Length 

 .40— .50 inch; 10—1.3 mm. 



The sexes exhibit the same differences as in the other species but 

 not in so conspicuous a degree. In the male the thorax is distinctly 

 longer than wide, narrowed in front, the sides feebly arcuate and the 

 hind angles more divergent. 



The thorax in the female is as broad as long, not narrowed in front, 

 the sides more arcuate and the hind angles less divergent than in the 

 males. The elytra are also a little less deeply striate at middle, but 

 this is not so conspicuous in the specimens before me as in the other 

 black species. 



Occurs in California. 



A. carbonatus Lee. — Black, moderately shining, sparsely clothed with 

 short black pubescence. Thorax densely punctured, moderately convex, hind 

 angles rather strongly carinate and very little divergent; flanks of thorax be- 

 neath densely punctured in front, less densely posteriorly but without smooth 

 space, tip of prosternum flexed. Mesosternum not prominent. Elytra striate, 

 strise finely punctured, intervals moderately convex and moderately densely 

 punctulate. Length .40 — .64 inch ; 10 — 16 mm. 



Males. — Thorax less convex, sides less arcuate and more narrowed in front. 

 Elytral strise equally deep at base and sides. 



Females. — Thorax more convex, sides more a;rcuate scarcely narrower in 

 front, disc somewhat more coarsely punctured. Elytral strise near the suture 

 often less deep than those at the sides. 



With this species I have united coracinus Cand., the differences 

 given by that author being merely sexual. 



Occurs from Nebraska westward to California and Oregon. Imma- 

 ture specimens are brownish with brown pubescence. 



A. niorio Lee. — Closely resembling in general appearance the preceding 

 but more robust and of larger size. The thorax is convex rather sparsely 

 punctured on the disc, more densely at the sides, the surface being more 

 shining than in carbonatus, the hind angles are similarly carinate but the 

 angles are not at all divergent; beneath the flanks are similarly punctured. 

 The prosternal mucro is straight and smooth, the mesosternum rather promi- 

 nent. The under side of the body is also less punctured and more shining 

 than carbonatiia. Length .60 — .72 inch; 15 — 18 mm. 



The sexes also exhibit a variation similar to that of carbonatus but 

 to a more marked degree, recalling that of memnonius. 



The punctuation of the thorax is somewhat variable but is never so 

 dense as in carbonatus or dilaticollis. The form of the prosternum 

 will distinguish this species at all times from the former, while the 

 latter species has a very regularly and densely punctured thorax with 



