235 



consisting of 2+7 joints (see PI. XTV, Fig. 21) ; palpi and proboscis 

 not discernible in type specimen. Thorax short and broad, without 

 a distinct suture except at the anterior angles, where the prescutum 

 shows distinctly; scutcllum large and distinct. Abdomen slightly 

 flattened, with seven distinct segments, the incisions between the 

 segments very distinct (Fig. 28). Legs short and thick, the basal 

 joint of tarsus longer than the second ; tarsus subequal in length to 

 the tibia, the claws very small ; tibiae as long as the slightly thickened 

 femora, the apical spur absent. Wing venation as in Figure 22. 

 Type of genus, Forbcsomyia atra, n. sp. 



FORBESOMYIA ATRA, n. sp. 



Female. — Entirely black, opaque. The venter of the abdomen 

 slightly brownish. Wing veins vitreous with the exception of the 

 thick veins, which are brown. 



Head without distinct hairs except a very few short ones on the 

 face ; antenna slightly shorter than the height of the head, with 

 microscopic pilosity. Mesonotum, pleurae, and scutellum without any 

 distinct hairs or bristles, only microscopic pile present on the 

 mesonotum. Abdomen about three times as long as head and thorax 

 together, shaped as in Figure 28, Plate XIV; the surface with very 

 short, soft, decumbent hairs. Legs with very short surface hairs, 

 appearing bare except under a strong lens; the anterior surfaces of 

 the coxae with rather longer pale hairs. Wings bare, the costa 

 unf ringed, the posterior margin with distinct, though not long, fringe. 



Length, 2.25 mm. 



Localitv, Urbana, Illinois, November 7, 1913 (C. A. Hart and 

 J. R. Malloch). 



This genus is very difficult to locate properly in any of the 

 families, but finds its closest affinities with the Bihionidce. The 

 presence of ocelli, the short antennae, and the strong legs point to an 

 association with Scatopsc, to which the wing venation also bears some 

 resemblance. The absence of the cross vein is however peculiar to 

 Forbesouiyia. In the chironomid genus Tersesthes Townsend, we 

 have an approach to the same neuration, but there are radical differ- 

 ences even here, and the antenna of Tersesthes is quite different in its 

 structure. 



The single specimen upon which the genus and species are founded 

 was taken on a window of the basement of the Natural History 

 Building of the University of Illinois. Nothing is known therefore 

 of the early stages of the species, though it may be pointed out that 

 at the same time and place specimens occurred that were referable to 



