34 PROCEEDINGS OF THE NATIONAL. MUSEUM vol. 66 



notum moderately 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 broadly obsoletely emarginate in front of scutellum; 

 posterior angles acute, not projecting, but fitting closely to the 

 elytron; surface glabrous, densely, obsoletely granulose, with a few 

 coarse, obsolete and irregularly placed punctures intermixed. 

 Scutellum wider than long, glabrous, obsoletely granulose, with the 

 anterior angles rectangular. Elytra slightly wider than pronotum 

 at base, and widest at basal fourth; humeral angles broadly 

 rounded; sides feebly arcuately rounded to near middle, then 

 strongl}^ arcuately attenuate to the tips, which are conjointly 

 broadly rounded, the lateral margins rather strongly serrate pos- 

 terioTly, and when viewed from the side are nearly straight, with 

 a feeble sinuation for the posterior femora; each elytron with an 

 indistinct basal dej^ression, but with a broad, deep one behind the 

 humerus, broadly flattened along lateral margin, and extending 

 forward to the humeral angle; surface sparsely, obsoletely and 

 irregularly punctate, the punctures not arranged in rows, coarser 

 on basal region, but becoming obsolete posteriorly, clothed with a 

 few very short inconspicuous hairs, and the intervals more or less 

 obscurely rugose. Abdomen beneath moderately convex, finely, 

 sparsely and obsoletely punctate, and clothed with a few very 

 short, inconspicuous hairs ; intervals finely and obsoletely reticulate ; 

 last segment acutely rounded at apex, the portion in front of the 

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

 tip. Elytral epipleura narrow. Metasternum sparsely, deeply and 

 very coarsely punctate, and broadly, rather deeply arcuately 

 emarginate in front. Prosternum feebly arcuately emarginate in 

 front, the surface glabrous, smooth, and not distinctly punctate; 

 prosternal process three times as wide as the coxal cavities, sides 

 nearly parallel, and broadly rounded at apex. 



Length, 2.25 mm. ; width, 1.5 mm. 



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



Type.— C2it. No. 26983, U.S.N.M. 



Described from a unique male collected at the type locality during 

 September, 1921. 



PACHYSCHELUS MODICUS Kerremans 



Pachyschelus modicus Kekuemans, Ann. Soc. Ent. Belg., vol. 43, 1899, p. 355. 



This species is represented by two examples, one collected near 

 the mouth of the Mapiri River during September, 1921, and the 

 other at Huachi (Beni River) during the same month. 



