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rostrum, pass backward almost parallel to each other for about 

 one half the length of the cephalothorax, then diverge, 

 passing to the outer border of the pseudostigmata, with which 

 they fuse, and from the posterior border of which they turn 

 transversely toward the median plane, where they meet. 

 There is a single pair of stout hairs on the dorsal surface at 

 the base of the rostrum, which are curved towards the median 

 plane. Pseudostigma a circular chitinous ridge; pseudostig- 

 matic organ straight, slightly clavate, and directed anteriorly. 



Abdomen subrectangular, two thirds as broad as long, sides 

 convex, posterior end rounded. An irregular chitinous ridge 

 lies on each side near the median plane; about midway between 

 this ridge and the lateral margin of the abdomen is situated on 

 each side a more regular chitinous ridge which curves similarly 

 toward the lateral margin. There are several short, curved 

 bristles on the lateral margins, two rows parallel to the median 

 plane, and six rather prominent pairs near the posterior mar- 

 gin, all of which curve inward. Ventral plate triangular, 

 genital and anal covers together extending almost its entire 

 length. 



Anterior pair of legs about as long as the abdomen. 

 Tarsus of leg I longer than the tibia but not so stout; claw 

 of tarsus almost half as long as the segment itself. All the 

 segments of the legs except the tarsus possess stout, curved 

 bristles. The bristles of the tarsus are slender and more 

 numerous than those of the other segments. 



Length, 0.85 mm.; breadth, 0.48 mm. 



Under logs and in moss. Collected by J. Douglas Hood at 

 Urbana, 111., and by the writer at Areola, 111. 



Genus Hypochthonius C. L. Koch. 



Mandibles chelate; last pair of legs not distant from the 

 others; integument thin, little chitinized, variously colored; 

 abdomen with a transverse suture; cephalothorax not truncate 

 in front. 



One species, — rufulus. 



