262 MEMOIRS ON THE COLEOPTERA 



only one-half wider than the prothorax, pale luteous in color, with a 

 very broad black fascia on each from behind the humerus to the pale 

 sutural bead, a rounded marginal spot at the middle, the apices black in 

 distinctly less than apical third, prolonged along the suture, diminishing, 

 nearly to the oblique fascia and enclosing the usual pale subapical spot; 

 punctures moderately strong, perforate, separated by twice their diam- 

 eters to but little more, fine and relatively sparser apically. Length 

 (9) n.o mm.; width 3.7 mm. British Columbia, Keen. 



Recognizable very readily from crassipes and allies by the much 

 stouter head and prothorax, cuneiform and not parallel elytra in 

 the female, fuller tempora and many other features. 



In the crassipes group there is a very marked and constant 

 sexual difference in the form and ornamentation of the elytra, 

 these being strongly cuneiform in the male, with the basal two- 

 fifths to half wholly pale and devoid of maculation, excepting a small 

 marginal post-humeral black spot; there is a submedian black 

 fascia, usually broadly interrupted at the suture, and the posterior 

 third is solidly black, excepting a small pale subapical spot. In the 

 female the elytra are perfectly parallel, much more broadly obtuse 

 at apex, and there is always an oblique discal fascia from behind the 

 humeri to or toward the suture, a large rounded marginal spot at 

 the middle and a black area in rather less than apical third and 

 including a much larger pale area, the black area more or less pro- 

 longed anteriorly and narrowly along the suture, usually to the 

 oblique fascia. The coloration of the abdomen and antennae is 

 variable and they are generally much paler in the female; the 

 abdomen is narrowly fasciate with a darker tint in the female as 

 a rule. 



In treating of the allies of crassipes before me, I will not include the 

 distinct crassicornis, for the original description of the female of that 

 species states that it is ferruginous, shining, the elytra sparsely and 

 finely punctate, with the three fasciae and the black apex all connected 

 at the suture and margin; the prothorax is densely, anteriorly more 

 finely, punctate and apparently has the usual form of the crassipes 

 group; the antennae of the female are stout and not at all more 

 than half as long as the body; the length of the female type, which 

 is from an unrecorded part of California, is 15 mm. This could 

 by scarcely any possibility be the female of corusca, above described, 

 because the sculpture of the prothorax differs greatly and there 

 is no such marked sexual disparity in the antennae or coloration 



