The Pselaphid^ of North America. 255 



the base it is thicker, and is conically pointed near the middle. 

 Prothorax as wide as long, widest slightly behind the middle, 

 evenly vaulted, the neck as wide as the base. Sides slightly 

 impressed before and behind the middle, basal foveas small, 

 situated at the bottom of these impressions. Middle fovese 

 very small, the transverse sulcus conspicuous. Elytra across 

 the shoulders very slightly wider than the prothorax, sutural 

 lines parallel, sharply turned aside near the base, leaving there 

 a narrow elevated ridge. In the place of a discal line is a 

 broad basal depression, leaving a basal and a humeral ridge. 

 Disk very convex, sides strongly arcuate. Abdomen of 6 con- 

 vex, shorter, as long as the prothorax, segments nearly equal 

 in length, margin narrow. Legs long, slender, posterior tibiee 

 arcuate in 3, straighter in ?. The punctures and form of the 

 elytra very strongly resemble those of Bythimis hirclU. 



Habitat. Alleghan}- Mountains. Canada. Mountains of 

 Virginia. 



Scalenarthrus, Lecontc. 



S. HORNH, Lee. Reddish brown, impunctate, pubescence, 

 very fine sericeous. Length, 0.7 mm. Plate VII., Fig. 36 ?. 



Head wider than long, eyes large, prominent, disk of the 

 vertex as wide as long, frontal margin triangularly produced 

 and not separated from clypeus by a transverse impression, 

 supra-antennal elevations very inconspicuous, each one being 

 two very minute, black-pointed, sharp-pointed tubercles. Disk 

 behind the inter-antennal Hne i^at, quadrate, with rounded 

 angles, between the eyes are two hardl}^ visible punctures 

 mutually four times farther distant than from the eye. 

 Between the posterior limits of the eyes are two faint trans- 

 verse elevations. Antennce longer than the head and pro- 

 thorax, the first and second joints nearly equal cylindrical, 

 third to sixth half the size of the second, cylindrical. Seventh 

 to tenth gradually increasing in size, the tenth nearly as wide 

 as the second, the eleventh is fusiform, sharp-pointed, trun- 

 cate at the base and half as wide as long. Palpi with the 



