216 Illinois State Laboratory of Natural History. 



black dots below each, one above, and four in a square 

 between them. Anal prominence very large, bearing on 

 each side a very thick, subconical, pointed, recurved fleshy 

 horn. 



Tipula sp. {e). [Fig. 37, 38.] 



A lot of larvae from which the present species was bred, 

 were collected from some leafy hollows in the black soil 

 of the higher bottom-land on the west side of the river, 

 below station H, on several dates between April 13 and 

 23. There were two sizes of these larvsB, so closely simi- 

 lar in all respects that they were supposed to belong 

 to a single species. The pupae from these forms, however, 

 maintaining the difference in size, differed distinctly in 

 certain structures, although for the most part apparently 

 identical; and they were accordingly bred separately, and 

 each pupal skin was removed with its imago, as they 

 emerged. The remarkable fact now became apparent that 

 while the larger pupae gave the above species, those from 

 the smaller form were not only of a different species, but 

 of another genus, being Pachyrhina ferruginea. 



Both larvae were probably feeding on the wet decaying 

 matted leaves at the bottom of the little hollows in 

 which they occurred. 



None had pupated when examined April 26, some were 

 pupae May 1, and all of the present species had reached 

 this stage by May 3, from which the imago was obtained 

 May 7, thus making the pupal period about a week. 

 The same larva has also been taken by us at Urbana, 

 April 27. 



Aside from the fact that the size of this species is 

 about twice that of the Pachyrhina, the two larvae are 

 almost identical. In the Tipula, the transverse pale line 

 on the head above is broader, the darker transverse bars 

 of the body are more distinct, and the lower pair of stig- 

 mata! teeth are larger, with a more extensive and darker 



