232 DIPTERA OF NORTH AMERICA. [PART IV. 



Gen. XXIX. ULOMORPHA. 



Two submarginal cells; four posterior cells; discal cell closed; sub- 

 costal cross-vein near the tip of the auxiliary vein ; loings finely, but 

 densehi pubescent. Eyes glabrous. Antennie i6-jointed. Tibiae with spurs 

 at the tip ; empodia distinct ; ungues smooth. 



Rostrum short, palpi of moderate length, last joint slender, but 

 not much longer than the preceding ; front moderately broad. 

 Antenna} 16-jointed ; those of the male, if bent backwards, would 

 nearly reach the end of the thorax ; those of the female are shorter; 

 iirst joint cylindrical, comparatively short; the second short, as 

 usual ; the third oval, rather stout ; the following joints slender, 

 linear, with rather long verticils ; those of the male with a dense 

 pubescence on the under side of the flagellum. Collare moder- 

 ately developed. Feet moderately long and stout ; hairy. Spurs 

 of the tibise small, but distinct. Wings clothed with a short, 

 moderately dense, almost microscopic pubescence, which is 

 evenly spread over the whole surface ; it is not woolly, like the 

 pubescence of Erioptera, and does not affect much the trans- 

 parency of the wing. The subcostal cross-vein is near the tip of 

 the auxiliary vein ; the praefurca has its origin a little before the 

 middle ot the wing; this origin is slightly arcuated and sometimes 

 with a stump of a vein ; the marginal cross-vein is rather faint, 

 and placed at a considerable distance before the tip of the first 

 longitudinal vein ; the first submarginal cell is almost as long as 

 the second, its petiole being very short, and in some specimens 

 obsolete ; the inner ends of the second submarginal, the first 

 posterior, and the discal cells are almost in one line ; there are 

 four posterior cells ; the second has its inner end more or less 

 attenuated ; the portion of the fifth longitudinal vein, lying 

 beyond the great cross-vein, is arcuated ; the great cross-vein in 

 most specimens has the appearance as if it was too short for the 

 distance it has to cross over; it strains the two veins which it 

 connects ; the vein on the hind side of the discal cell shows this 

 strain very plainly, appearing angular at the point of intersection 

 with the cross-vein. 



The structure of the antennte and the venation (the presence 

 of only four posterior cells notwithstanding) seems to point to a 

 relationship with Limnophila recondita and its group ; perhaps 

 also to L. quadrata. The external resemblance of Ulomorpha 



