THE FIREFLIES OR LIGHTNING BUGS. 829 



truncate or even somewhat emarginate in front; seventh ventral 

 segment of male truncate, the eighth exposed. The tarsal claws of 

 all our known Indiana species are armed with a long acute tooth, 

 causing them to appear broadly cleft. In another group, which 

 may yet be found to be represented in the State, the claws are 

 armed with a broad, nearly rectangular, basal tooth. Eight spe- 

 cies have been taken in the State. 



KEY TO INDIANA SPKCIES OF PODABRUS. 



. Eighth ventral segment (if male triangular, flat, rounded at tip. 



&. Elytra distinctly dilated on the sides, their elevated lines strongly 

 marked ; antennae stouter. 



c. Size larger, 11-13 mm.; thorax more than twice as wide as long. 



1574. TRICOSTATUS. 



cc. Smaller. 7-8 mm. ; thorax not much wider than long, distinctly 

 narrowed in front. 1575. RUGOSUIA s. 



b&. Elytra not or scarcely dilated on the sides, their elevated lines in- 

 distinct. 



d. Elytra rather coarsely rugose. 



e. Thorax twice wider than long; color smoky brown or dull black. 



1576. BASILARIS. 



ee. Thorax but little ^yider than long; color, except sides of thorax, 

 shining black. 1577. FRATER. 



(Id. Elytra finely rugose; thorax but little wider than long. 



/. Elytra black without pale margins; median impressed line <>!' 

 thorax distinct DIADEMA. 



ff. Margins and suture of elytra narrowly pale; median line of tho- 

 rax feeble or wanting; second and third joints of an tenure sub- 

 equal. 1578. MODESTUS. 

 (ia. Eighth ventral of male oblong with sides parallel, obtusely rounded at 



tip. 



(l. Head suddenly narrowed behind the eyes, neck short; head and tho- 

 rax uniform reddish-yellow. 1579. TOMENTOSUS. 

 (jg. Head much prolonged behind the eyes, neck long. 



n. Head sparsely punctured behind ; thorax feebly punctured. 



1580. PROTENSUS. 



///;. Head and thorax both coarsely, the latter sparsely punctured. 



15S1. BRUNNICOLLIS. 



1574 (4879). PODABRUS TRICOSTATUS Say, Bost. Journ. Nat. Hist., I, 1835. 



158 ; ibid. II, 635. 



Elongate, robust. Black ; front of head and sides of tho- 

 rax reddish-yellow. Antennae about half the length of body, 

 joints two to four increasing in length. Head and middle 

 of thorax densely punctured, the sides of latter broadly flat- 

 tened and reflexed. Elytra very broadly dilated on middle 

 third, densely rugose, each with three strongly elevated lines. 

 Male elytra less dilated and antennae longer than in female. Fig. 323. < l*. 

 Length 11-13 mm. (Fig. 323.) (After Knobel.) 



Lawrence and Perry counties; rare. May 31- June 17. 



