NORTH AMERICAN COLEOPTKRA. .>7 



A. COiicavilS Say. — Moderately elongate, pale reddish brown, sliinin^. Am- 

 tcnnns a little paler. Head convex, not tuberculate, smooth, a few fine punctures 

 posteriorly; clypeu.s broadly feebly emarginate, rounded each side of emargina- 

 tion, sides arcuate, fimbriate, genre moderately prominent, but obtuse. Thorax 

 nearly twice as wide as long, the sides feebly arcuate, nearly parallel j>osteriorly. 

 more arcuate in front, margin not explanate, finely fimbriate, hind angles very 

 obtuse, base arcuate, with feeble sinuation near the hind angles, a scarcely evi- 

 dent marginal line; disc moderately convex, with extremely fine punctures 

 sparsely placed with larger punctures near the base and sides more widely dis- 

 tant. Elytra a little narrower at base than the thorax, humeri very obtuse, sides 

 feebly arcuate, disc deejtly striate, strite finely punctured, intervals convex, 

 smooth. Body beneath sparsely punctate, metasternum almost entirely smooth 

 at middle. Mesosternum not carinate, coarsely punctured with a large smooth 

 space at middle. Anterior tibiie smooth in front, strongly tridentate externally, 

 not crennlate above, the first tarsal joint shorter than the .second. Posterior 

 femora with a line of coarse punctures near the knee, first joint of tarsus as long 

 as the next three. Length ..32-. 34 inch ; 8-8..^ mm. 



In the male the anterior tibial 8])iir i?; sliorter and stouter, the 

 upper middle tibial spur stouter than in the female. The thorax of 

 the male has fewer coarse punctures at the sides and very few along 

 the apical margin, while in the female a small central space on the 

 disc is alone free of large punctures. 



Occurs from Georgia to Missouri, Kansas and Colorado. 



A. riibidiis Lee. — Form moderately elongate and convex, pale reddish 

 bro'.vn, shining. Antennse slightly paler. Head moderately convex, obsoletely 

 tuberculate each side, surface sparsely ])unctate ; clypeus broadly feebly emar- 

 ginate, on each side distinctly angulate the sides arcuate and fimbriate, gense 

 moderately prominent, but obtuse. Thorax not twice as wide as long, the sides 

 feebly arcuate and gradually narrowed to the front, margin not explanate, 

 .scarcely fimbriate, hind angles obtusely rounded, base regularly arcuate and with 

 fine marginal line ; disc moderately convex sparsely punctured with coarse and 

 fine punctures intermixed, the punctures coarser and closer toward the sides. 

 Elytra as wide at base as thorax, the humeri ol)tuse, sides feebly arcuate, disc 

 moderately deeply striate, strias closely and finely punctured, intervals convex 

 smooth. Body beneath sparsely punctate. Mesosternum- not carinate, coarsely 

 punctured smoother at middle. Anterior tibiie smooth in front, tridentate ex- 

 ternally, obsoletely crenulate above, the first joint of tarsus shorter than the 

 second. Posterior femora with a row of coar.se punctures near the knee, the 

 first tarsal joint not as long as the next three. Length .24-.36 inch ; (5-9 mm. 



The male has merely a shorter and stouter anterioi* tibial spur, the 

 thoracic sculpture does not apparently differ in the sexes. 



This species resend)les concavu,^ in size, color and general appear- 

 ance, and may be distinguished, especially, by the angulation of the 

 clypeus on each side of the emai'gination. There are other les.s con- 

 spicuous difterences observable in the desci'iption. 



