218 R. E. SNODGKASS. 



on the middle of its distal edge, and another longer and slenderer 

 one on the anterior angle. The latter projection is covered basally 

 on its outer side by a lateral lobe. This is the characteristic feat- 

 ure of the second appendage. 



The guard of the penis is triangular in lateral view. The lateral 

 parts are transversely continuous into each other below. There is 

 thus formed between them a wide space in which the end of the 

 penis lies normally. In the specimen from which figure 77 was 

 drawn the end of the penis {p.) was projecting from the genital 

 chamber. The posterior dorsal angles of the guard are swollen into 

 large, pale, tumid, semi chitinous lobes. The guard arises just above 

 the posterior edge of the sternum, which is deeply notched. The 

 sides of the notch bear two pad like, chitinous lobes. In front of 

 these there is a narrow membranous space extending forward to the 

 anterior rim of the sternum, which consists of a slender, arched bar 

 of chitin. 



Tipula uniciucta Doane (PI. XV, figs. 109, 110, 111, 114). 



The posterior segments of the abdomen form a thick club shaped 

 enlargement. The eighth segment is the widest, and its posterior 

 I'im is hoi'izontal. The exposed part of the ninth is hemispherical 

 and sits upon the eighth like a ball in a socket. The eighth tergum 

 is small, but the sternum is very large and projects posteriorly and 

 upward behind the hypopygium (fig, 109). It ends in a small 

 transverse lobe bearing a fringe of long hairs. There is a rather 

 wide depressed area between this lobe and the posterior (i. e. ven- 

 tral) face of the hypopygium. From the floor of this depression 

 there project two lateral, conical elevations (fig. 109, a) each bear- 

 ing a long, slender, curved, l)lade-like appendage (fig. 109, b), the 

 two crossing each other mesially (fig. 114). 



The plates of the hypopygium have ordinary forms. The poste- 

 rior margin of the tergum is deeply and narrowly cleft. The part 

 on each side is produced posteriorly as a large tapering process. 

 The sternum consists of two large lateral plates connected only by a 

 narrow anterior median bridge of chitin below. Back of this bridge 

 is a wide membranous area whose posterior margin hangs downward 

 as a free fold (fig. 109, c). The pleurum is distinct from the ster- 

 num on each side. It is triangular, with the distal apex produced 

 into a blunt, tapering point. 



