39. Side margins of prothorax rather narrow; coxal plates distant from 



the mesocoxal cavities by fully half their own length leptapsis 



Side margins of prothorax very broad; coxal plates distant from 

 mesocoxal cavities by much less than half their own length discors 



40. Rufo- or brownish testaceous elytra a little darker; coxal plates 

 large; metasternal wings sublinear length about 7/^2 mm.; (Nebraska 



to British Columbia.) .' clavatus 



A. cordatus Lee. Proc. Acad. Nat. Sci. Phila., 1853, p. 226. 



Very easily recognized by the small subcordiform thorax, which is not approached 

 by any other of our species except rectus. The color is not truly black, the upper 

 surface being rather piceous, obscurely tinged with rufous, and feebly aenescent. 

 The four anterior tarsi of the male are moderately dilated, the protarsal claws 

 not sexually modified. Length 8.7 to 9.2 mm. 



A not uncommon species in the Rocky Mountain Region, and known 

 to me from Montana (Missoula) ; Colorado (Colorado Springs and 

 Leadville) ; New Mexico (Pecos) ; and Utah (Ft. Douglas). The 

 type is from Santa Fe, New Mexico. 



A. rectus Lee. Annals Mag. Nat. Hist. (4) IV, 1869, p. 375. 



Closely similar in general aspect to cordatus, but the prothorax is scarcely cordi- 

 form, the sides less convergent and nearly straight posteriorly. The color is more 

 truly black, the upper surface entirely devoid of rufous marks or shades in the 

 few examples seen. Length 9 mm. 



This is a distinctly rarer insect in collections than the preceding. It 

 was described from Vancouver, and is known to me also from Wash- 

 ington State (Wawawei M. C. Lane). 



A. spinipes Sharp. Biol. C. Am. I, 2, p. 32. 



Moderately broadly oval, subdepressed, outline of thorax and elytra nearly con- 

 tinuous ; black, opaque ; labrum, clypeal margin, two obscure vertex spots, mouth, 

 antennae and legs, rufous. Surface densely deeply reticulate, the meshes small, 

 variable in form and size, and in part on the elytra having the appearance of 

 small flattened granules. Head two-thirds as wide as the prothorax, the latter rath- 

 er more than twice as wide as long, distinctly lobed at base, lateral bead rufescent, 

 sides sinuate at front angles in the female. Elytra seven-tenths as wide as long, 

 sides evenly arcuate, apex obtusely rounded, each with the usual series of coarser 

 punctures; minute punctulation indistinct because of the density and roughness 

 of the reticulation. Antennae short and rather thick, the intermediate joints only 

 about one-third longer than wide. Prosternal process broad, feebly convex or 

 flattened, widely margined, the apex bluntly acute ; metasternal wings rather wide 

 between the middle coxae and coxal plates. Sculpture beneath and legs much as 

 usual, the hind tibiae with a row of coarse elongate punctures along the inner 

 margin. Male with anterior tarsi a little dilated basally, the first and second 

 joints only clothed beneath with glandular hairs, which are tipped with small 

 palettes; the middle tarsi undilated and quite devoid of sexual pubescence; pro- 

 tarsal claws not perceptibly modified; no sexual difference in surface sculpture. 

 Length 6.8 mm. ; width 3.5 mm. 



