Horn.] i-bo [Nov. 5, 



them to be inseparable. Chaudoir proposes to separate these forms by 

 their dentate or simple humeri, merula and pinguis with dentate humeri, 

 and rusticus and liaplomus with simple humeri. These characters ai'e not 

 by any means as constant as could be desired. It is true that forms can be 

 selected typifying about four species, but the vast mass of the specimens 

 would occupy the intermediate ground. Locality also has but little to do 

 with the variation except that the form usually called merula appears to be 

 peculiar to the Southeastern States. Length very variable .36 — .56 inch ; 

 9 — 14 mm. 



The male has the first four joints of the anterior tarsi dilated and pubes- 

 cent beneath, the middle tarsi are nearly as widely dilated, the first joint 

 very feebly pubescent at tip only. In the female the anterior tarsi are 

 slightly broader than the middle, the first joint not stouter. 



Occurs everywhere in the Atlantic region east of the Kocky Mountains. 



12. A. carbonarius Say. Form oblong, black, feebly shining (^ or 

 opaque 9 • Clypeus with two setigerous punctures on each side. Thorax 

 broader at base than apex, sides feebly arcuate, hind angles obtuse, base 

 truncate, side margin depressed, broadly near the base, base externally and 

 side margin punctulate, distinctly (^, obsoletely^- Elytra oblong, sides 

 nearly parallel (^, or slightly arcuate 9> surface finely striate, intervals 

 slightly convex (^ or flat $ . Body beneath smooth, shining. Prosternum 

 punctured and w'ith erect hairs, intercoxal process coarsely punctate. 

 Length .52 inch ; 13 mm. 



In the male the anterior and middle tarsi are dilated and pubescent 

 beneath, the first joint of the middle pubescent over half its surface. In 

 i\\e female the characters are as in rusticus. 



Occurs from the Middle States to Colorado. 



B — a, nigrita Group. 



Species oblong, surface either shining or opaque, glabrous. Terminal 

 spur of anterior tibiae (^ 9 dilated at middle. Posterior tarsi slender, 

 nearly as long as the tibiae, the first joint nearly as long as the next two 

 together, the fourth joint feebly emarginate. Elytra striate, often very 

 finely, intervals rarely punctulate, tip distinctly sinuate, second stria with 

 a distinct dorsal puncture. 



Male. Anterior tarsi broadly dilated, the first four joints densely pu- 

 bescent beneath, middle tarsus nearly as widely dilated, the first joint pu- 

 bescent at tip only, the next three densely pubescent over their entire sur- 

 face. 



Female. Anterior and middle tarsi slender or very feebly broader, not 

 pubescent beneath. 



The clypeus may have one or two setigerous punctures on each side, the 

 number of species in the first series being greater than the second. Those 

 with one puncture follow naturally after the rusticus group. 



