The Pselaphid.^ of North America. 23 



when taken conjointly, broader than long, narrow-shouldered, 

 arcuate behind the middle, sutural lines entire, dorsal lines 

 well impressed at the base, abbreviated before the middle; 

 shoulders rounded, unarmed. Abdomen with the first dorsal 

 three times as wide as long, bearing three transverse basal im- 

 pressions, of which the middle one is smaller; the triangular 

 margin is very narrow. Legs long, posterior tibice with a 

 long, needle like spur; the 3 tibi« are thicker and slightly 

 curved; antennje with the joints cylindrical, decreasing in 

 thickness from the first to the seventh; the eighth, ninth, and 

 tenth, obconical, gradually larger, the eleventh acute-ovate. 

 ? antenna? of the same form but shorter. 



Habitat. Between the thirty-sixth parallel and the lakes. 



B. SIMPLEX, Lee. Red or reddish yellow, polished; pubes- 

 cence sparse. Length, 1,9 to 2 mm. 



Head of 5 longer than wide, the frontal margin produced, 

 retuse, front concave behind the margin; vertex broadly con- 

 vex, smooth, foveas small, nearly nude, the circumambient sul- 

 cus very shallow at the sides and in front; the part outside of 

 this sulcus is finely scabrous. In the ? the frontal margin is 

 not produced and the entire vertex is smooth. AnienncE regu- 

 lar, with no sexual marks. Proihorax with the middle and 

 lateral grooves deep, the two tubercles near the base stout, 

 acute, and on each side near the basal angles are two small 

 acute teeth; the lateral margin is fiat from the bottom of the 

 lateral groove outward. Elytra indistinctly punctulate, the 

 shoulders acutely angulate, disk convex, sutural hues parallel, 

 the discal ones hardly more than shallow, longitudinal, short 

 impressions, from the third or external basal puncture. Abdo- 

 men polished, impunctate, the three basal, pubescent, trans- 

 verse impressions equal in width, the median separated by 

 tw^o distinct short cariuce. Legs slender, the posterior tibiae 

 with a long terminal spur. 



Habitat. Northern Illinois, near Lake Michigan. 



B. GLOBOsus, Lee. Red brown, poHshed, punctulate; pubes- 



