272 • GEO. H. HORN, M. D. 



specimens are somewhat variable and the hind angles are sometimes 

 scarcely more than rectangular. 



At the same time Motschulsky describes two other species, striatus 

 ventricosus. The latter I feel quite sure is merely a variety of Menetriesi. 

 The other may possibly be interstitialis, ffubb., but I am unwilling to 

 suppress a name founded on a good description to adopt one quite other- 

 wise. 



Occurs in the Mammoth, Cave City, Saltpetre and Ronald's caves. 



A. tenuis Horn, Trans. Am. Ent. Soe. 1871, p. 327. 



This is the most slender species in our fauna. The hind angles of the 

 thorax are slightly prolonged backwards. The elytra are faintly striate 

 on the disc, the intervals with slight traces of punctuation, and the entire 

 surface extremely finely alutaceous. The recurrent sutural stria is well 

 marked, The tarsal claws are extremely slender and nearly straight. 



My specimens were collected by Prof. Cope in the Wyandotte cave, of 

 Southern Indiana ; those possessed by Dr. LeConte are from the Brad- 

 ford caves. 



A. pusio Horn, Trans. Am. Ent. Soc. 1868, p. 125. 



This is our smallest species. The thorax is not larger than the head, 

 narrowed behind, the hind angles not prominent, the base nearly squarely 

 truncate and the basal impressions very deep. The striae of the elytra 

 are evident only near the suture, and the sutural stria is very distinctly 

 recurved. The surface is shining, the intervals near the base very finely 

 punctulate and with very short pubescence. 



I have seen but three % specimens of this species, all collected by 

 Prof, Cope in Erhart's cave, Montgomery county, Virginia. 



A. eremita Horn, Trans. Am. Ent. Soc. 1871, p. 325. 

 A species somewhat resembling tenuis, but broader. The thorax at 

 base is very squarely truncate, and the elytra less striate and more dis- 

 tinctly alutaceous than in any other species in the present list. 

 One £ specimen collected in Wyandotte cave. 



A. pubescens Horn, Trans. Am. Ent. Soc. 1868, p. 126. 

 The humeri are distinctly serrulate, the surface distinctly alutaceous, 

 feebly striate and with an extremely fine pubescence, which appears to 

 be more persistent than in the other species. 



Collected in Cave City, Saltpetre and Ronald's caves. 



A. aildax n. sp. — Rufo-testaceous, shining, head slightly darker. Thorax 

 one-third broader than long, scarcely narrowed at base, sides slightly arcuate in 

 front, feebly sinuate in front of the hind angles, which are rectangular but not 

 prominent, base squarely truncate, apical and median lines moderately distinct. 



