The Pselaphid^ of North America. 43 



ing together. Prothorax one-third longer than the head, 

 widest two-fifths from the base, where it is slightly wider 

 than long, evenly and continuously arcuate to the base, and 

 convergent and slightly arcuate toward the neck, which latter 

 is half as wide, and the base four-fifths as wide as the width 

 of the prothorax; sides minutely crenate posteriorly; disk 

 very convex, imperceptiblv and sparsely punctulate, with a nar- 

 row, linear, median sulcus, extending from the neck to the 

 base, crossed by a similar, straight, linear, transverse sulcus, 

 ending each side in a small, pubescent, fovea. Elytra from 

 side to side very convex, longitudinally nearly straight; across 

 the shoulders they are as wide as the prothorax, and equal to 

 the length of the suture; across the tip they are one-fifth 

 wider; shoulders rather prominent, sides nearly straight; sutu- 

 ral fines slightly arcuate, interval punctulate, base trifoveate, 

 the two outer fove^e with shallow longitudinal impressions in 

 the place of the discal lines, of which the outer ones are one- 

 half longer than the inner ones, and may be traced to two- 

 thirds of the elytral length from the base. Abdomen very con- 

 vex, the segments sub-equal, border narrow, flat, the basal 

 dorsal with two carinas including less than one-fourth of the 

 total width. Legs long, slender, tarsal claw with a fine hair- 

 like appendage; anterior coxte conical, pointed, posterior coxse 

 flat, transversely oval. Besides the transverse oval impression 

 on the last ventral in the 3, the acute tubercle of the frontal 

 margin is prolonged backward so as to interrupt the trans- 

 verse sulcus. 



Habitat. East of the Mississippi River. 



Oropus, Casey. 



O. STRiATUS, Lee. ( Trichonyx striatus Lee.) Yellowish 

 brown, uniformly colored; pubescence moderately dense and 

 long, abundant; body sparsely punctulate. Length 2 mm. 

 Plate XI, Fig. 102. 



Head wider for one-half its length, eyes not prominent, 

 large, not as long as the tempora, which latter are but slight- 



