130 GEORGE II. HORN, M. D. 



tured on the disc, more densely and coarsely toward the sides which are moder- 

 ately rounded ; base finely margined. Elytra oval, broader behind the middle, 

 moderately striate, striae rather coarsely punctured, interspaces flat, distantly 

 punctulate ; apices of elytra rufous. Body beneath and legs black, hind tibire 

 slender. Length .20 inch; 5 mm. 



Occurs from Pennsylvania to Illinois. 



A. coloradensis, n. sp. — Elongate oval, black shining. Head coarsely punc- 

 tured ; clypeus emarginate and on each side elevated into an acute tooth ; front 

 behind the emargination distinctly impressed. Thorax moderately convex, 

 sides feebly rounderl, base distinctly margined, surface coarsely but sparsely 

 punctured with finer punctures intermixed. Elytra broader behind the mid- 

 dle, moderately striate, striae finely' punctured, interspaces very feebly convex 

 and sparsely obsoletely punctulate. Body beneath black, legs piceous, hind 

 tibise stout. Inner spur of middle tibia of male slightly hooked at tip. Length 

 .26 inch ; 6.5 mm. 



For the unique in my cabinet, I am indebted to Mr. James Ridings, 

 who found them rather abundantly in Colorado. 



This species recalls the form oi: ui-si)ius. 



A. bicolor, Say, Journ. Acad, iii, 1823, p. 212. — Oblong oval, slightly depressed, 

 black, shining. Head coarsely punctured, more densely at the sides and front. ; 

 clypeus emarginate and rather strongly angulate on each side. Thorax moiler- 

 ately convex, sides feebly rounded, surface coarsely punctured with finer punc- 

 tures intermixed, base distinctly margined. Elytra oblong, rather deeply 

 striate, striae finely punctured, interspaces moderately convex and punctulate. 

 Pro- and mesosternum piceous, metasternum, abdomen and legs yellowish. 

 Length .18— .24 inch ; 4..5— 6 mm. 



The elytra are usually black or piceous, but in several specimens be- 

 fore me they are dark ferruginous^with the alternate intervals (2 — 4 — 

 6) showing paler rounded spots. The species may be easily known 

 from any in our fauna by its dark color above and yellow legs and ab- 

 domen. 



Occurs from Canada to Texas. 



A. dentiger, Lee. Proc. Acad. 1858, 6'>. — Oblong oval, piceous black, shining. 

 Head sparsely but coarsely punctured and finely rugose infi'ont; clypeus at 

 middle truncate and on each side an acute slender tooth, outside of which the 

 clypeus is rather deeply sinuate. Thorax moderately convex, sparsely but 

 coarsely punctured on the disc, more densely at the sides, sides feebly rounded 

 gradually narrower in front, base distinctly margined. Elytra broader behind 

 the middle, feebly striate, striae distantly punctured, interspaces flat, very 

 sparsely and finely punctulate. Body beneath piceous. Male. Spur of anterior 

 tibia slightly arcuate, and hooked at tip; inner spurof middle tibiashort broad 

 and, deeply emarginate at tip. Female. Unknown. Length .26 inch; 6.5 

 mm. 



This species is easily known in the group by the two slender teeth 

 of the clypeus. In the preceding species the angulation of the clypeus 

 is broad at base, the teeth of deatijer are slender. 



