314 DIPTERA OF NORTH AMERICA. [PART IV. 



rather broad surface; epistoma narrow, very much prolonged, 

 pointed at the end ; proboscis with large suctorial flabs ; palpi 

 very long, all the joints being elongated. Eyes large, separated 

 by a moderately broad interval on the upper side of the head, and 

 a broader one on the under side. The antennae of the male are 

 twice the length of the head and the thora.x, or more ; first joint 

 very small ; the second but very slightly larger ; the flagellum is 

 filiform, and consists of (apparently IS) subcylindrical joints of 

 nearly equal length ; only the first is a little longer ; it is clothed 

 with a microscopic down, without any longer hairs. The thorax 

 is very small in comparison to the size of the body ; the collare 

 is not visible, the head being in contact with the mesonotum ; the 

 thoracic suture is deeply sinuate in the middle ; the metathorax 

 is large and convex. The abdomen of the male is long and 

 narrow, attenuated at the basis; the forceps (Tab. IV, fig. 31, 

 from below, 31 a from above) consists of two pairs of digitiform, 

 somewhat curved coriaceous appendages. 



The ovipositor of the female, which I have not observed on living 

 specimens, does not show the usual horny, pointed valves. I per- 

 ceive only a pair of small, very little projecting valvules, apparently 

 of a thin, coriaceous consistency, sickle-shaped, rounded at the tip. 

 Feet long, femora remarkably slender, especially on their basal 

 half; tibiiB somewhat stouter than the femora, with small spurs at 

 the tip; the first joint of the tarsi is somewhat longer than the 

 four following taken together, incrassated, spindle-shaped ; the 

 second joint is once and a half the length of the third ; the fourth 

 and fifth are very small, and their length, taken together, is hardly 

 equal to the third joint ; the empodia are broad, transverse. 

 Wings shorter than the abdomen, small and narrow for the size 

 of the insect ; glabrous, hyaline ; the stigma is hardly indicated 

 by a narrow streak along the first longitudinal vein ; the tip of the 

 auxiliary vein is opposite the tip of the fifth vein ; no subcostal 

 cross-vein ; marginal cross-vein at the tip of the first longitudinal ; 

 prsefurca very short ; first submarginal cell nearly three times the 

 length of the second ; three posterior cells, none of the branches 

 of the fourth vein being forked ; the inner ends of the first sub- 

 marginal and of the three posterior cells are nearly in one line ; 

 the section of the fifth posterior vein beyond the great cross-vein 

 is bisiuuated (as in Ptychoptera) ; only one longitudinal vein 



