32 PBOCEEDINGS OF THE NATIONAL MUSEUM vol. 6G- 



convex, densely, finely and obsoletely reticulate, and nearly gla- 

 brous ; last segment acutely rounded at apex, the area in front of the 

 marginal groove acutely rounded, with a rather acute tooth at the 

 tip. Elytra epipleura narrow. Metasternum sparsely and coarsely 

 punctate, and broadly, rectangularly emarginate in front. Pro- 

 sternum feebly arcuately emarginate in front, the surface glabrous, 

 obsoletely reticulate, and not distinctly punctate ; prosternal process 

 nearly four times as wide as the coxal cavities, sides feebly rounded, 

 and broadly truncate at apex. 



Length, 2.2 mm. ; width, 1.4 mm. 



Type locality. — Cavinas (Beni River), Bolivia. 



Type.—Q2.t. No. 26981, U. S. N. M. 



Described from a unique male collected at the type locality during 

 January, 1922. 



PACHYSCHELUS AENEICOLLIS (Kirsch) 



Bracliys aencicollis Kirsch, Berl. Ent. Zeit., vol. 17, 1873, pp. 360-361. 



Two specimens of this species were collected at Huachi (Beni 

 River), during September, 1921. 



PACHYSCHELUS VIRmULUS (Kirsch) 



Bracliys viridulus Kirsch, Berl. Ent. Zeit., vol. 17, 1873, p. 362. 



This species is represented by a single example collected at Riber- 

 alta (Beni River), during January, 1922. 



PACHYSCHELUS NIGRIVENTRIS, new species 



Female. — More narrowly cuneiform than cavinas, considerably 

 longer than wide, broadly rounded in front, strongly attenuate pos- 

 teriorly, distinctly narrower behind than in front, and rather 

 strongly shining; head, pronotum and scutellum fuscous, the head 

 with a feeble aeneous tinge, and the pronotum narrowly, obsoletely 

 margined with green; elytra bluish-black, with a feeble violaceous 

 reflection ; beneath piceous, and more shining than above. 



Head feebly convex, deeply embedded in the prothorax, and broad- 

 ly, longitudinally grooved from vertex to epistoma, the groove rather 

 deep on the front, but becoming obsolete on the vertex; surface 

 glabrous, densely and finely granulose, with a few coarse, irregularly 

 placed punctures intermixed. Pronotum feebly convex, three times 

 as wide as long at middle, much narrower in front than behind, and 

 widest at base ; sides strongly obliquely arcuate from base to anterior 

 angles, which are acutely angulated; anterior margin broadly and 

 deeply arcuately emarginate; base transversely sinuate, acutely 

 emarginate at elytral lobes, and nearly truncate in front of scutellum ; 

 posterior angles acute, projecting slightly beyond the humeral 

 angles of elytra and fitting closely to them ; surface sparsel}" clothed 



