THE SHORT-WINGED SCAVENGES BEETLES. 



401 



Casey, Thos. L. — "Revision of the Sienini of America North of 

 Mexico," 1884, pp. 1-206. (Published privately.) 



Two genera comprise the subfamily, both of which are repre- 

 sented in Indiana. 



KEY TO GENERA OF STENIN^E. 



a, Paraglossa not narrowed at base; cheeks prominent; elytra each with 

 a large reddish-yellow spot. XLI. Dianous. 



aa. Paraglossa strongly narrowed at base; cheeks very small, usually in- 

 visible from above. XLII. Stenus. 



XLI. Dianous Leach. 1819. (Gr., ' 'to meditate.") 



Rather robust species having the eyes smaller and more widely 

 separated than in Stenus; antenna? long and slender; abdomen 

 strongly margined at the sides. Two species are known from the 

 United States, one of which has been taken in the State, while the 

 other, D. ceeruleseens Gyll, ha,s been taken about the Great Lakes 

 and probably occurs in northern Indiana. 



KEY TO SPECIES OF DIANOUS. 



a. Elytra scarcely longer than wide ; punctuation coarse and sparse. 



777. NITIDULUS. 



aa, Elytra distinctly longer than wide ; punctuation fine and dense. 



CCERULESCENS. 



777 (2301). Dianous nitidulus Lee, Proc. Bost. Soc. Nat. Hist, XVI. 

 1874, 272. 



Black or dark steel blue; elytra each with a large rounded pale spot 

 behind the middle; pubescence very fine and sparse, visible only on head 

 and abdomen. Head with two wide, shallow grooves between the eyes, 

 separated by a convex ridge; finely and rather closely punctured. An- 

 tennae reaching middle of thorax, third joint one-half longer than fourth. 

 Thorax subcylindrical, widest at middle, narrower at base than apex, with- 

 out median impression ; surface rather coarsely, not closely punctate. Ely- 

 tra slightly narrower than head, coarsely, rather sparsely and evenly punc- 

 tate, the punctures separated by twice their own width. Abdomen finely 

 and sparsely punctate. Length 4.5 mm. 



Floyd County; scarce. October 4-October 9. Taken beneath 

 stones on the bank of the Ohio River. 



XLII. Stenus Lat. 1796. (Gr.. "narrow.") 



A very large genus of closely related forms which for conven- 

 ience are separated into the following groups : 



