24 O. H. HORN, M. D. 



Oi^iTODKM, Lee. 

 O. pnncticollis, n. sp. — Form slender, surface sparsely clothed with 

 very short pubescence. Head very densely and coarsely punetured, black ; 

 antennte CJ, ) longer than the head and thorax, subserrate. Thorax blaik. 

 moderately shining, longer than wide, sides rery feebly arcuate, hind angh-s 

 slightly divergent and moderately strongly carinate and an extra-angnlitr 

 carina parallel with the margin, short but well defined, base of thorax bisinu- 

 ate and opposite the scutellum deeply eraarginate, the emargination obtusely 

 toothed at middle; surface strongly conrex, coarsely, deeply, moderately 

 densely and evenly punctured. Scutellum oblong, shining, slightly impressed 

 longitudinally. Elytra testaceous, suture and base piceous, surface moderately 

 shining, (sutural stria alone entire), vaguely and irregularly punctured and at 

 base with a slight humeral oblique impression. Body beneath piceous, thorax 

 less coarsely punctured than above, metasternum and abdomen sparsely and 

 finely punctured, shining. Legs testaceous. Length .24 inch; 6 mm. 



This species reseoibles tenuicollis, Rand., in form and coloration, 

 and appears to differ only in the punctuation of the thorax, which is 

 .shinin<r, and nearly smooth in tenuicollis, while in the present species 

 it is very coarsely, deeply and rather densely punctured. 



One .specimen collected by Dr. Elliot Coues, near the northern 

 boundary of Dacota, while naturalist of the North Western Boundary 



Survey. 



APLASTUS, Lee. 

 Several new species having appeared, it seems advisable to present 

 some scheme, by which they may be distinguished, founded on char- 

 acters least subject to variation. The following will serve for those 

 at present known : 



Third joint of antennas similar in size and shape to the fourth. 

 AntenniB slender, feebly serrate, three basal joints only pilose; sides of tho- 

 rax parallel, not margined, hind angles strongly divergent. 



angusticollis. 

 Third joint of antennte always much smaller than the fourth, sometimes globu- 

 lar, never triangular; antennse with short erect hairs. 

 Thorax not margined. 



Antennae strongly serrate, joints 2, 3 very small nearly equal, together 

 slightly longer than half the fourth. 

 Elytra scarcely striate, thorax very sparsely punctate.. ..tenuiforuiis. 

 Elytra moderately deeply striate, thorax coarsely and moderately 



densely punctate corymbitoides. 



Antennae serrate, joint 3 more than twice the length of 2, and together 



nearly as long as the fourth speratus. 



Thorax with ihe sides distinctly margined, at least at base. 



Form slender, tarsi slender and as long or longer than their tibiw. Color 



ferruginous. Pubescence coarse optfttUM. 



Form shorter, less slender, thorax more convex, tarsi never as long as their 

 tibiw. Color piceous. Pubescence fine molcstUH. 



