THE CANADIAN ENTOMOLOGIST. 59 



yellow in basal half or third, beyond nearly black; stylus nearly 

 black. 



Prothorax very slightly broader than long and about one and 

 one-fourth times as long as width of head, broadest at posterior 

 third; surface roughened; bristles short, scattered. Meso- and 

 metathorax yellow, without differentiated dorsal plates, the former 

 with anterior ventral angles darkened with brown or gray. Wings 

 totally lacking. Legs short, stout, rugose; fore femora brown, 

 fore tibiae yellow apically and along middle, tarsi yellow; middle 

 and hind legs yellow. 



Abdomen rather large and heavy, about 1.6 times as wide as 

 prothorax, broadest at segment 6; segment 10 with a longitudinal 

 dorsal suture; all bristles very short and inconspicuous. 



Measurements of holotype: Length 1.16 mm.; head, length 

 of exposed portion .108 mm., width .150 mm.; prothorax, length 

 .192 mm., width .204 mm.; pterothorax, width .220 mm.; abdo- 

 men, width .324 mm. Antennal segments: 1, 27m; 2, length 

 42/i, width 34m; 3, length 36m, width 22m; 4, 36m; 5, 36m, 6, 

 56m; 7, 10m; 8, 13m; total length of antenna, .26 mm. 



Male. — Much like female, but smaller (length .7 mm.).. 

 Segment 9 of abdomen with two pairs of dorsal spine-bearing 

 tubercles, the posterior pair more widely separated than the 

 anterior. 



Measurements of allotype: Length .696 mm.; head, length 

 of exposed portion .090 mm., width .116 mm.; prothorax, length 

 .138 mm., width .152 mm.; pterothorax, width .160 mm.; abdo- 

 men, width .196 mm. 



Described from two females and one male, taken at Welling- 

 ton, Kansas, August, 1910, on wheat, by E. O. G. Kelly. 



Though apparently very close to P. vejdovskyi Uzel, an un- 

 common European species, it differs in several important respects 

 from the description and figures given by Lzel in his "Mono- 

 graphic" Cognatus has much stouter antennae, with the first 

 segment completely hidden in dorsal aspect by the vertical 

 protuberances; the eyes are less prominent; the genal tubercle is 

 flattened and the spine borne conspicuously at the tip in 

 vejdovskyi is greatly reduced in size in cognatus; and, finally, the 

 mesothorax of cognatus is yellow instead of black. 



