164 BULLETIN" 14 5, UNITED STATES NATIONAL MUSEUM 



clothed with moderately long, semierect, whitish hairs; prosternal 

 lobe broad, rather strongly declivous, and broadly, feebly emarginate 

 in front; prosternal process broad, the sides parallel to behind the 

 coxal cavities, then obliquely narrowed to the apex, which is acute. 

 Tibiae slender, the anterior and middle pairs armed with a very 

 small tooth on inner margin at apex. Posterior tarsi shorter than 

 tibiae, and the first joint about as long as the following three joints 

 united. Tarsal claws dissimilar, anterior and middle ones cleft near 

 apex, the teeth nearly equal in length, and the inner one not turned 

 inward ; posterior claws cleft near middle, and the inner tooth much 

 shorter than outer one. 



Fdmale. — Differs from the male in having the front of head more 

 cupreous, slightly wider, sides more parallel, and the surface less 

 densely pubescent; first and second abdominal segments convex or 

 feebly flattened at middle; tibiae unarmed at apex, and the tarsal 

 claws similar on all feet, cleft near middle, and the inner tooth much 

 shorter than outer one. 



Length, 5.5-13 mm. ; width, 1.5-3 mm. 



Type locality. — Of anxius, North America; present location of 

 type unknown to writer. Of torpidus, Lake Superior; type in Mu- 

 seum of Comparative Zoology. Of gravis, Lake Superior; type in 

 Museum of Comparative Zoology. 



Distribution. — This species has a wide distribution, and will prob- 

 ably be found wherever its host plants occur, but so far it has not 

 been reported from the southern part of the United States, except in 

 the Rocky Mountain region, where its range extends southward to 

 Arizona and New Mexico. Material has been examined from the 

 southern part of Canada (Alberta, New Brunswick, Ontario, Quebec, 

 and British Columbia) and from various localities in the following 

 States: Arizona, Colorado, Connecticut, Illinois, Indiana, Iowa, 

 Maine, Massachusetts, Michigan, Minnesota, Montana, New Hamp- 

 shire, New Jersey, New Mexico, New York, Ohio, Oregon, Pennsyl- 

 vania, Rhode Island, South Dakota, Utah, Virginia, West Virginia, 

 and Wisconsin. 



Variations. — The species is quite variable in coloration, which varies 

 from a uniform olivaceous black to bluish gray, with a more or less 

 cupreous reflection, to those having the pronotum distinctly more 

 reddish cupreous, and which resembles some forms of arcuatus Say. 

 The depressions on the pronotum are extremely variable, in some ex- 

 amples the median depression is entire, whereas in others it is divided 

 into two parts, and occasionally one of these depressions is only 

 feebly indicated, and again in some specimens there is a small round 

 depression on each side of the middle anteriorly, but in others these 

 depressions are entirely absent. The elytra! costae are usually feebly 



