THE WHIRLIGIG BEETLES. 



241. 



bronzed and finely reticulate; labrum rounded in front and ciliate ; 

 scutellum invisible; elytra with nine slightly impressed striae which 

 are sometimes very indistinct. Front tarsi of males moderately 

 dilated and densely clothed beneath with papilla?, forming; an elon- 

 gate, narrow brush. Four species are known from Indiana, while 

 another may occur. 



KEY TO INDIANA SPECIES OF DINEUTES. 



a. Sides of thorax and elytra with a bronzed submarginal stripe; length 

 12-15.5 mm. vi'ttatus. 

 aa. Sides without submarginal stripe; length not over 11 mm. 



1). Under surface uniform brownish-yellow. 474. discolor. 



1)1). Under surface black or bronzed. 



c. Sutural angles of elytra rounded in both sexes; femora of male 

 toothed. 475 emarginatus. 



cc. Sutural angles distinct in female ; femora of male not toothed. 

 cl Sutural angles of both sexes produced . backward ; tips of female 

 elytra feebly separated. 476. assimilis. 



dd. Sutural angles of elytra of male rounded ; those of female pro- 

 duced backward with the tips strongly separated. 



477. HORNII. 



B. villains Aube has a range which probably includes southern 

 Indiana, but it has not yet been taken in the State. 



474 (1534). Dineutes discolor Aube, Spec. Gen.. VI, 1838, 784. 

 Oblong-oval, moderately convex, narrowed in front. Above black- 

 bronzed, shining; under surface brownish-yellow to straw color. Elytra 

 with side margins at outer apical angle and tips slightly sinuate, * the 

 sutural angles weakly produced ; femora of male with a triangular tooth. 

 Length 11.5-13 mm. 



Steuben, Kosciusko, Putnam and Martin counties; very "common 

 in East Fork of White River. June 26-September 3. Easily 

 known by the narrower front half of body and pale under surface. 



475 (1538). Dineutes emarginatus Say, Trans. Amer. Phil. Soc, II, 1823 



108 ; ibid. II, 519. 



Rather broadly oval, moderately convex. Above black or blackish- 

 bronzed, not very shining; beneath black, very shining, slightly bronzed; 

 middle and hind legs, narrow margin and tip of abdomen, paler. Side 

 margins of elytra in male, not in female, slightly sinuate near tips ; sutural 

 angles broadly rounded. Length 10-11 mm. 



Pond near University farm, east of Mitchell, Lawrence County: 

 scarce. August 7. Probably throughout the southern half of 

 State. 



