226 MEMOIRS ON THE COLEOPTERA 



thorax not twice as wide as long, the moderately converging sides feebly 

 arcuate, rounding apically ; outer stria very fine, rather close to the margin 

 and not attaining the middle, the inner rather fine, straight and virtually 

 entire; elytra only moderately transverse, the rounded sides more con- 

 verging posteriorly; striae smooth and rather fine though deeply incised, 

 four entire, fifth and sutural of equal length, both abruptly obsolete in 

 rather more than basal third; humeral and subhumeral entirely obsolete, 

 the oblique humeral extremely fine; inflexed flanks slightly concave, 

 somewhat finely tristriate; propygidium slightly concave toward each 

 side, the punctures rather coarse but everywhere remotely separated; 

 pygidium small, very convex, smooth, gradually finely, then more evi- 

 dently though sparsely, punctate basally; prosternal lobe unusually 

 acutely rounded, strongly beaded throughout; mesosternum rectilinearly 

 truncate; anterior tibiae with four very moderate teeth, the distal finely 

 and equally bifid. Length 3.7 mm. ; width 2.6 mm. New York (Catskill 

 Mts.) H. H. Smith. 



This species is entirely isolated in the americanus group, not only 

 in elytral striation but in the acutely rounded and strongly margined 

 prosternal lobe. The coloration may possibly be due to immaturity, 

 at least in part. 



The second division of this group, indicated above, is the larger, 

 and of the seven species in my collection only three pollutus 

 and nubilus of LeConte and davisi Schf . have as yet been described ; 

 the other four, of which the first is somewhat aberrant in group 

 characters, may be defined as follows: 



Hister abducens n. sp. Broadly oblong-oval, convex, polished and 

 black throughout, the upper surface without evident minute punctulation 

 except feebly on the head, which is even on the surface, with the stria 

 entire, transverse on the front; the left mandible is carinate only in basal 

 third; prothorax only moderately transverse, the moderately converging 

 sides very feebly arcuate, but little more so toward the apical angles, 

 which are blunt and narrowly rounded; outer stria fine,, rather close to the 

 edge, not extending to the middle, the inner fine, not quite entire, the 

 intermediate surface flat and with some sparse and extremely minute 

 punctulation; elytra transverse, only two-fifths longer than the prothorax. 

 the sides strongly arcuate, more converging posteriorly, the three entire 

 dorsals moderate and shallow, subeven, the fourth fine, present only near 

 base and toward apex, the fifth completely obsolete, the sutural fine, 

 wanting in basal third and toward apex; humeral and subhumeral striae 

 completely obsolete, the oblique humeral distinct though very fine; 

 inflexed sides flat, finely tristriate; pygidia shining, the propygidium with 

 very evenly distributed equal and moderate punctures, separated by 

 two to three times their diameters; pygidium convex, smooth, gradually 

 finely, then more distinctly, loosely, punctate basally; prosternal lobe 

 obtusely rounded, not margined, the mesosternum with an excessively 

 feeble and indefinite medial sinuation; anterior tibiae moderately tri- 



