Femora of male strongly sinuate beneath at apex, tibiae 



pedunculate at base femoratus 



Size smaller (less than 4 mm.), form broader; color gen- 

 erally paler with better defined elytral clouds behind the 

 middle fraternus 



14. Elytra without impressed lines 15 



Elytra with more or less evident impressed lines in basal half, at 



least in the male, feeble or wanting in the female 19 



15. Punctures of elytra evidently unequal 16 



Punctures of elytra denser and nearly uniform in size 17 



16. Last ventral with an obtuse tumidity each side, more prominent in 



the male tumidiventris 



Last ventral not tumid." punctilineatus 



17. Clypeus margined. 



Form more distinctly obovate, sides of thorax not continuous 



with those of the elytra masculinus 



Form less distinctly obovate, thorax larger, sides straight, 



slightly sinuate, continuous with sides of elytra fastidiosus 



Clypeus not margined 1 8 



18. Sides of thorax feebly divergent posteriorly, not continuous with 

 sides of elytra: elytral vittae narrow, much abbreviated in front. 



semivittatus 



Sides of thorax normally divergent, nearly continuous with sides of 

 elytra. 



Size smaller (3.6 to 4 mm.), claws of front tarsi (<) unusually 



elongate, not very unequal in length or thickness. hudsonicus 



Size larger (5 to 5.8 mm.) 



Form broader, surface beneath alutaceous in both sexes, 



claws of front tarsi (<) very unequal unguicularis 



Form more elongate, surface beneath not alutaceous, claws 



of front tarsi (c?) stout, rather short, equal oregonus 



19. Size larger (4.5 to 5.5 mm.), color varying from pale yellow, with 

 vittate elytra to nearly uniformly piceous; punctuation very coarse 



with intermixed fine punctures, less obvious in the female 



impressopunctatus 



C. acaroides Lee. 



Rotundate oval, rufotestaceous, body beneath often darker, brownish or even 

 piceous with the prothorax and abdominal apex pale ; elytra with the suture 

 narrowly, a broader more or less abbreviated subsutural stripe (often inter- 

 rupted), and two external discal spots, blackish; the markings are, however, 

 very variable through confluence or suffusion. Antennae and legs pale, the 

 tarsi sometimes dusky. Head and thorax finely, not very closely punctate ; elytra 

 more coarsely and closely and very evenly so. Coxal plates very coarsely 

 closely punctate, abdominal segments very minutely densely punctulate and dull, 

 the basal segments at sides with scattered shallow coarser punctures. Clypeus 

 very finely margined ; elytra with a fine acute submarginal carina extending 

 forward from the middle but not attaining the base. Length 2.1 'to 2.4 mm.; 

 width 1.3 to 1.5 mm. 



Var. marginipennis Blatch. 



Similar in all essentials to the "typical form, but with an extreme suffusion of 



