34 GEO. H. HORN, M. D. 



front, the sides feebly arcuate, the hind angles liroadly rounded, base feebly ar- 

 cuate, lateral margin narrowly explanate, more broadly near the hind angles 

 where there is a broad, but shallow depression ; disc moderately convex, smooth 

 and shining, a few coarse, but shallow punctures opposite the base of each ely- 

 tron and others in the depression and close to the side margin. Elytra a little 

 narrower at base than the thorax, humeri very obtuse, disc very finely striate, 

 the strife scarcely visible at the sides ; stria? very finely and rather closely punc- 

 tured, intervals flat and polished. Mesosternum not carinate. Body beneath 

 sparsely punctate, shining. Posterior femora with a row of coarse punctures 

 near the knee ; first joint of hind tarsus as long as the next three. First joint 

 of anterior tarsus shorter than the second, the tibia smooth in front and not ser- 

 rulate above the teeth. Length .32 inch ; 8 mm. 



Male. — Spur of anterior tibia elongate triangular, broader and truncate at tip. 

 Middle and posterior femora ciliate at basal half of posterior margin. 



Female. — Spur of anterior tibia stout, curved and acute at tip. Femora not 

 fimbriate. Thorax with more numerous and convex punctures at the sides. 



This species is notable for its size, color and highly polished sur- 

 face. I have changed the name as Mulsant had used the same for 

 another species, the description of which appeared a few months 

 earlier the same year. 



Occurs in Texas and Kansas. 



Series I-l>. 



Front not tuberculate. Thorax at sides not explanate, without 

 basal marginal line, Mesosternum distinctly carinate between the 

 coxae. Anterior tibiie punctate in front, the first tarsal joint longer 

 than the second. 



The last two characters together are not known in any other spe- 

 cies in our fauna. At present but two species are known, they closely 

 resemble each other superficially, but may be separated in the fol- 

 lowing manner : 



Posterior tibife stout ; first joint of posterior tarsus not as long as the next three. 



rnbeoliis. 

 Posterior tibite slender ; first joint of posterior tarsus longer than the next three. 



stercorosus. 



These belong to the fauna of the Atlantic I'egion, and the second 

 seems more widely spread and common. 



A. riibeolus Beauv. — Form moderately elongate and convex, rufo-ferru- 

 ginous or pale castaneous, shining. Antennae rufo-testaceous. Head convex, 

 sparsely finely punctate, front not tuberculate ; clypeus feebly emarginate at 

 middle, the angles each side obtuse, the sides arcuate, the angles each side obtuse, 

 the sides arcuate, gense scarcely more prominent than the eyes. Thorax slightly 

 narrowed in front, sides feebly arcuate, hind angles very obtusely rounded, base 

 broadly arcuate without marginal line, disc convex, at middle very sparsely finely 



