176 DIPTERA OF NORTH AMERICA. 



pedicelled or sessile (sometimes pedicelled in the < and sessile 

 in the 9 ; sometimes of the same structure, pedicelled or ses- 

 sile, in both sexes). 



Diplosis Loew. The second longitudinal vein reaches the margin 

 of the wing at or beyond its tip (fig. 2). Antennae of the male 

 26 (2 + 24) jointed, sometimes with one rudimental joint 

 more; joints pedicelled, simple joints alternating with double 

 ones (Tab. I, f. 11 and 12), seldom all joints simple. Antennae, 

 of the 9 14 (2 + 12) jointed, sometimes with one rudimental 

 joint more; joints pedicelled, cylindrical. 



Asphondylia Lw. The second longitudinal vein reaches the margin 

 of the wing a little beyond its tip (as in fig. 2). Antennae of 

 both sexes with the same number of joints; the latter, cylin- 

 drical, sessile, with a short pubescence and without verticils. 

 (A single European species is known.) 



Hormomyia Lw. The second longitudinal vein reaches the margin 

 of the wing either at or beyond the tip. Thorax more or less 

 gibbose, frequently extending over the head in the form of a 

 hood. Joints of the antennas pedicelled ; those of the 9 

 pedicelled or sessile. 



Colpodia Winn. The second longitudinal vein forms a curve before 

 the cross-vein and joins the margin a little beyond the tip of 

 the wing (fig. 3). Cross-vein rather large, oblique. (A single 

 European species is known in the female sex only; the joints 

 of its antennae are pedicelled. This sub-genus, which is un- 

 known to me, must be very difficult to distinguish from Epi- 

 dosis.) 



B. Cross-vein very oblique, originating at the root of the first 

 longitudinal vein (fig. 4).* 

 Dirhiza Lw. Second longitudinal vein hardly undulating before 



the cross-vein; joints of the antennae sessile or almost sessile 



in both sexes. (A single species is known.) 



* The sections A and B, as denned by MM. Loew and Winnertz, seem to 

 be somewhat difficult to distinguish. According to the latter, the cross 

 vein in the section B almost assumes the appearance of an intercalary 

 longitudinal vein; it begins at the root of the first longitudinal vein, runs, 

 although very indistinct, alongside of it and then turns obliquely towards 

 the second longitudinal vein, which thus almost appears to be its continu- 

 ation, or, in other words, to have two roots. 



