154 CHARLES W. LENG. 



the entire body is thinly clothed with white hair, mostly decumbent. 

 The tarsi of the male are pubescent beneath as usual, but very little 

 wider than those of the female, and the last ventral segment is 

 syraetrically emarginate, otherwise this species might be placed in 

 the repanda group. 



PusiLLA group. 



Thorax slightly convex, subcylindrical uot margined, palpi pale at base; front 

 bald, striate to the labrum ; elytra not serrulate, punctulate, sericeous. 



Elytral markings almost or quite lacking pusilla. 



Almost black, all markings indicated var. pusilla. 



Almost black, markings reduced to apical lunule, or immaculate. 



var. terrictola. 

 Blue or green, markings indicated or immaculate; punctures distinct. 



var. cyanella^ 

 Elytral markings usually complete. 

 Middle band oblique. 



Markings attaining or confluent on the margin cinctipennis. 



Markings separated from the margin imperfecta. 



Middle band perpendicular to the margin liinaloiiga. 



In addition to the characters used above, which seem the most 

 obvious, pusilla may be known from cinctipennis and imperfecta by 

 the more uniform sericeous surface and more convex thorax. The 

 variety terricola seems to be very feebly differentiated, but I regret 

 that I have not been able to see enough specimens to form a definite 

 opinion. Tlie differences between cinctipennis and imperfecta seem 

 very constant and they have a different geographical range. 



C pusilla Say, 1817, Jour. Ac. Phil., i. 21 ; Trans. Am. Phil. Soc, new ser., i, 

 424, pi. 13, fig. 12; Uej. Spec, ii, 432; Lee. Ann. Lye, iv, 183; Trans. 

 Am. Phil. Soc, xi, 45; Schaupp, I.e., p. 95; pi. 3, fig. 71. 

 Length 9-11 mm.=.36-.44 inch. 



Habitat. —Flsitte Kiver Valley, on moist mud; Devil's Lake, N. 

 Dak. (Wickham); Ariz. (Blanchard) ; Kan., Neb., Dak., Hudson 

 Bay Terr., Cal. (Schaupp). 



"Opaque black, not metallic, head striate, thorax almost quad 

 " rate, slightly narrowed behind, rounded at the sides and hairy, 

 " elytra gradually wider behind the shoulders, sparsely punctate, with 

 " humeral lunule curved, apical lunule inflected anteriorly, and a 

 " median oblique streak dilated at the margin, all slender and white, 

 " beneath sparsely hairy at the sides ; tibiaj pale at base ; labrum 

 " white, tridentate ; palpi of both sexes pale, blackish at apex. 

 " Varies with the elytra black immaculate." (LeConte.) 



