THE HISTER BEETLES. 



627 



KEY TO INDIANA SPECIES OF ACBITUS. 



a. Thorax without a row of punctures across the base. 1203. exigutjs. 

 0(7. Thorax with a row of punctures across the base; prosternum much 

 longer than wide, its striae not more divergent in front than at base. 



1204. STRIGOSUS. 



1203 (3649). Acritus exigutjs Erichs., Jahrb., 1834, 208. 



Broadly oblong-oval, slightly convex. Dark reddish-brown, shining. 

 Thorax rather coarsely and sparsely punctured. Elytra more coarsely but 

 not more densely punctured than thorax, the marginal stria rather deep, 

 entire. Prosternum more than twice as long as wide, its surface with very 

 few punctures. Front tibia? slender. Length 1 mm. 



Southern half of State ; frequent beneath bark of elm and other 

 logs. Gregarious and probably hibernates. April 9-November 22. 



1204 (3654). Acritus stbigosds Lee, Proc. Phil. Acad. Nat. Sci., 1853, 289. 

 Rounded-oval, moderately convex. Dark brown, shining. Thorax sparsely 



and rather finely punctured, the basal row of punctures slightly curved and 

 not extending on either side beyond the middle of the base of elytra. Ely- 

 tra coarsely punctured, less distinctly on basal third. Metasternum coarsely 

 and rather sparsely punctured. Length 0.8 mm. 



Marion County; scarce. Taken by H. Morrison from the sides 

 of a bridge abutment on which they had alighted to bask in the sun- 

 shine ; also by sifting. April 23-November 8. 



XIII. deletes Horn. 1873. 



The species of this genus are separated from those of Acritus ' 

 only by the absence of a scutelium. In such minute forms this 

 character is very difficult to distinguish except under very high 

 power. Four species are known from the United States, two of 

 which have been taken in Indiana. 



1205 (3657). .33letes politus Lee, Proc. Phil. Acad. Nat. Sci., 1853, 290. 

 Rounded-oval, convex. Brown, shining, surface wholly devoid of punc- 

 tures. Prosternum twice as long as wide ; mesosternum with longitudinal 

 grooves. Length 0.8 mm. 



Throughout the State; frequent. Occurs beneath bark and in 

 dead leaves and other rubbish about the base of trees where it may 

 be taken by sifting. April 9-November 28. 



1206 (3660). JSletes simplex Lee, Bost. Journ. Nat. Hist., V. 1845. 84. 

 Oval, moderately convex. Reddish-brown, shining. Thorax and ely- 

 tra very sparsely and finely punctured, the former with a basal row of 

 coarser punctures the middle ones of which are linear or sulciform. Pro- 

 sternum nearly as broad as long. Meso- and metasterna smooth, the suture 

 coarsely punctate. Length 1 mm. 



