THE CANADIAN ENTOMOLOGIST. 175 



Original coloration somewhat uncertain because of long preservation 

 of specimens in too weak alcohol, but apparently ferrugino-testaceous with 

 the legs and vender more yellowish, and the caudal ventral plates and legs 

 and the prosternum and head darker ; antennae darker than legs but 

 somewhat paler than head. Length 17-20 mm. 



Locality. — Kooteno Co., Idaho. 



Genus Paitobius gen. no v. 

 Head as in LitJiobius, as also are the mouth-parts, nearly. Coxos- 

 ternum of second maxilke with narrow median membranous strip which is 

 thin and bent dcrsally. Prosternum bearing uniformly 2 + 2 teeth of which 

 the inner one on each side is always borne conspicuously farther forward 

 than the outer, the line tangent to apices of teeth curving cephalad from 

 sides to middle, i.e., being procurved. Spine at ectal angle bristle-like 

 apically. Anterior margin narrow, the lateral slope beginning almost 

 directly from ectal tooth. Antennae always short, consisting of from 27 

 to. 35 articler. Coxal pores uniseriate, circular. (Last two pairs of cox» 

 laterally armed). Penult legs always armed with two claws; and legs also 

 armed with two claws (excepting in naiwatus). Dorsal spines of anal legs 

 always 1,0,3,1,0; of penult, 1,0,3,1,0 to 1,0,3,2,1. Anal and penult legs 

 always short and distinctly furrowed longitudinally along dorsal surface of 

 third to fifth articles ; furrow more distinct on third article and especially 

 in the male in which this article is wider or more crassate than in the 

 female. Gonopods of male small, conical, directed caudo-ectad and nearly 

 always wholly concealed by the sternite. Gonopods of female with the 

 claw always distinctly partite, three lobes being typically present or rarely 

 one of these almost obliterated. Basal spines rather slender and acumin- 

 ate from base, distad. Body of adults always showing a deeper violaceous 

 or purplish or reddish-purple pigment, modifying the coloration, more 

 or less, of entire body ; and in preserved specimens, at least, distinctly 

 colouring especially the muscles. Anal legs always dark, proximally with 

 the tibiae and tarsi conspicuously paler, usually yellow. The head and 

 dorsum smooth and shining, never rugose. (In all known species the 9th, 

 nth and 13th, of 6th, 7th, 9th, nth and 13th, or of 7th, 9th, nth and 

 13th dorsal plates with posterior angles produced.) 



Type. — P. carolince Chamberlin. 



Distribution — The South-eastern States. 



In addition to the type, the genus includes the following species : 

 naiwatus Chamberlin, tabius Chambeihn, juventus Bollman, and simitus 

 Chamberlin. 



