THE WHIRLIGIG BEETLES. 239 



4(i;! (15(1.",). Gyrini's MiNUTrs Fiib., Syst. Eleut, I, ISOl, 270. 



Elougate-(.\-al. Alxivf blue-black; sides and margins of elytra bronzed; 

 beneath brownish-yellow, abdomen black, last- ventral segment piceous. Me- 

 dian line of thorax and scntellum with a fine carina ; mesosternum with a 

 (loep median furrow. Length 4— 1..5 mm. 



Woodland pond near Broad Ripple. Marion County; scarce. 

 I\Iay 1."). Readily known hy tlio carinate scntellum and bicolored 

 under surface. 



4(;4 (IfiOS). ■ ({YRiNii.s FRATEKNis (.'ouii.. Can. Nat., lind Scr., II, (iO. 



Elongate-oval, r.-ither robust. Above bluish-black, polished, not bronzed; 

 under surface uniform dark reddish-brown. Tijis of elytra broadly rounded. 

 Length (l mm. 



Pine, Lake County and Hudson Lake,Laporte County; scarce. 

 'May 20-August 20. Known l)y the more robust form and entire ab- 

 sence of bronzed lustre. 



41;") (l.";i3). (rYRiNUs VENTRALis Kirby. Faun. Bor. Amer.. IV. ls;^,T. M). 



Oval. Above black, ver.y highly polished, iridescent ; 

 margins, sides and sntui'e of elytra bronzed; beneath re;I- 

 dish-brown, sides and tip of abdomen a little paler. Length 

 itX>-7 mm. (Fig. VS2. ) 



Northern half cf State; common. March 14- 

 Scptemlier 19. A handsome species, easily known 

 by its larger size and more brilliant iridescent sur- 

 face. 



G. aqiiiris Lee, 6.5 mm. in length, is recorded 

 from the Lliddle States and Lake Superior. 

 4(;(; (3509). Gy'RINUS ^neolds Lee, I'roc. Phil. Acad. Nat. Sci., ISC.S, .'UiS. 

 Elongate-oval. Above uniformly black-l)ronzed, very shining; beneath 

 dark reddish-brown, the last two ventral segments paler. Elytral punc- 

 tures in both this and Uiiibatus larger and more distinct than in ilicUnniH. 

 Length ."i-.^.S mm. 



Lo^v meadow ponds near Bass Lake, Starke County, and Hunt- 

 ingburg, Dubois County; scarce. April 8-May 9. 

 4(;7 (1511). <;YKi?irs DiciiRors Lee, Froc. Phil. Acad. Nat. Sci., ISd^. 3(W. 

 Resembles the next but wholly without lironzed lustre. Punctures of 

 elytral striie smaller, more crowded. I,ength 4.5 mm. 



Lake ^ilaxinkuckec; scarce. August 17. 



KiS (1510). (Jyrincs LiiiRATis Say. Trans. Amer. Phil. Soc. II, 1,^2:1. 10!); 

 il)id. II, .")2U. 



Short, broad, but little attenuate behind. Above black, shining, dis- 

 tinctly bronzed, esjiccially so on margins and suture of elytra and front 

 margin of thorax; lieueath reddisli-brown. the middle segments of abdo- 



n(;-2:!4()2] 



