23S 



FAMILY V. GYKIXID^E. 



ad. Last ventral elongate, conical; labrnm prominent; scutelluui invisible; 



length mm. 



GYKETES. 



I. 



t 



GYRINUS Linn. 1733. (Gr., "a circle or ring.") 



Our members of this genus are smaller, more 

 narrow and more convex than those of the next. 

 They have eleven rows of distinct punctures on 

 each elytron which, when held in a certain light, 

 usually reflect a golden tint; the legs are always 

 reddish-brown or yellowish in hue. (Fig. 121.) 

 On account of the close resemblance between the 

 species, their definition and recognition is quite 

 difficult. The following have been taken or per- 



Fig. 121. 1, beetle; 2, larva. 



(After Packard.) haps occur in Indiana. 



KEY TO INDIANA SPECIES OF GYRINUS. 



it. Scutellum finely but distinctly cariuate. 403. MINUTUS. 



mi. Scutellum flat. 



1>. Under side margin of thorax and epipleura brownish-yellow. 

 c. Under surface uniform brown or brownish-yellow. 

 '/. Larger, 6-7 nrni. 



r. Polished black, not bronzed or iridescent. 404. FRATKKNTS. 

 re. IJlack. very highly iridescent, margins and sides bronzed. 



/. Tips of elytra rounded; form broader. 40. r . VENTRAI.IS. 



//. Tips of elytra truncate; form more narrow. A^TIRIS. 



'/'/. Smaller. 4.r>-">.n mm. 



(]. Form more elongate; tips o!' elytra rounded, covering only half 



of last ventral segment. 

 //. Margins, sides and suture of elytra distinctly bronzed. 



400. ^ENEOLUS. 



//7i. Elytra not at all bronzed. 407. DICHROUS. 



////. Form short, broad; tips of elytra nearly truncate, almost or 

 wholly covering the last ventral segment. 40X. LIMBATUS. 

 re. Under surface black or piceous. bronzed ; last ventral segment red- 

 dish-brown. 



i. Upper surface finely alutaceous ; length 7-S mm. 40!). AFFINIS. 

 ii. Upper surface not alutaceous; length 5.5 mm. 470. ncEoi.i s. 

 I>1>. Under side margin of thorax and epipleura metallic black. 

 j. Front margin of mesosteruum regular in form. 

 /.-. Elytra highly polished, distinctly bronzed. 



/. Smaller and more narrow. f mm.; outer rows of elytra 1 



punctures but little stronger than inner. 471. AXALIS. 



//. Longer and broader, 7 mm.; outer rows of elytral punctures 



distinctly impressed. 471'. ROREALIS. 



/,7,-. Elytra black, scarcely polished and not at all bronzed. 



473. LUGEXS. 



././. Front margin of mesostermim trilobed, with an obli(|iie im]tression 

 each side; under surface black; length .". mm. PECTORALIS. 



