Entomology of the Illinois River. 217 



border within [Fig. 37]. As to the pupae, I can only 

 compare the females, as I have not the male of this 

 species. The row of teeth next behind the tarsi— that 

 of the fourth abdominal— consists in the Tipula of about 

 eight small teeth, the middle ones distinct, and directly 

 back of the tarsi. In the Pachyrhina, those directly be- 

 hind the tarsi are wanting, leaving only a small pair on 

 each side, as on the preceding segment in both species. 

 The conical mass at the apex of the female abdomen 

 [Fig. 38] is prolonged in the Tipula, greatly exceeding 

 the posterior pair of dorsal teeth, while in the Pachy- 

 rhina it is short, not extending beyond the tips of those 

 teeth [Fig. 40]. 



Larva [Fig. 37].— Head with the pale transverse line 

 rather broad at middle; last antennal joint larger, 

 brownish, mandibles with the blunt teeth larger and 

 longer than in eluta. 



Body blackish fuscous with a brownish tint, covered 

 with very fine brown pubescence. Anterior divisions 

 with only two distinct transverse impressed lines above 

 and below, forming three folds between the true and 

 false sutures; first abdominal and posterior divisions 

 elevated into a low transverse ridge of darker color, 

 bearing the usual four black setae above and four pairs 

 of setae below, each pair appearing like one seta ; anterior 

 divisions with one lateral seta, posterior divisions and 

 first abdominal with two, thoracic segments with three 

 or four, vertically arranged. 



Last segment [Fig, 37] with stigmatal field and anal 

 prominence whitish; above the former, four narrow erect 

 fleshy teeth; the inner pair sharper and slightly re- 

 curved, posterior faces black, narrowly pale margined; 

 outer pair more slender, diverging, with a black streak 

 on posterior faces. Stigmatal plates black; below them 

 the other pair of teeth, short and inconspicuous, not se- 

 tiferous, tips blackish, sometimes slightly margined with 

 fuscous on inner face; in front of them a black dot; 



