ERIOCERA. 253 



brownish stripes above, the intermediate ones approximated; 

 pleurae with a hoary reflection on their lower part ; halteres pale 

 at the basis, knob blackish ; coxae hoary, trochanters and basis 

 of the femora yellowish-tawny ; femora and tibiae tawny, with 

 brown tips ; tarsi brown. Abdomen dark brownish, downy ; 

 lateral edges, especially beyond the third segment, yellowish, 

 venter paler; forceps tawny ; its structure like Tab. IY, fig. 29. 

 Wings tinged with brownish ; costal and subcostal cells of a 

 more saturated tawny color ; stigma oblong, brown, placed 

 between the subcostal and stigmatical cross-veins ; first sub- 

 marginal and first posterior cells about equal in length ; the 

 second submarginal is longer ; five posterior cells ; petiole of the 

 second cell about as long or a little longer than the cell itself. 



Female. Like the male, but much larger ; body of a reddish- 

 brown, instead of a grayish-brown tinge, less downy ; the antennae 

 are not longer than the head and thorax taken together ; they 

 have no spines, but only sparse hairs ; ten indistinct joints can be 

 counted ; ovipositor ferruginous ; upper valves elongated, almost 

 imperceptibly arcuated, ending in a blunt point. 



Hab. Trenton Falls, N. Y. ; Massachusetts (Scudder). I 

 possess two males and one female. The front femora of one of 

 the males are much shorter than those of the other. 



2. E. longicornis Walk. % and 9- — Obscure cinerea, thoracis 

 vittis obscuris ; antennis maris corpore duplo longioribus ; in pagina 

 inferiori serie spinarurn parvarum ; halteribus pallidis ; cellulis posteri- 

 oribus quatuor ; ovipositor ferninse brevis, valvis superioribus brevissimis, 

 obtusis. 



Dark gray, thorax with blackish stripes ; antennae of the male twice the 

 length of the body, on the under side with a row of small spines ; halteres 

 pale ; four posterior cells ; ovipositor short ; upper valves shorter than 

 the lower ones, obtuse. Long. corp. 0.4 — 0.5. 



Syn. Anisomera longicornis Walker, List Dipt. Brit. Mns. I, p. 82. 



Arrhenica longicornis 0. Sacken, Proc. Ac. Nat. Sc. Phil. 1859, p. 245. 



Head gray, frontal bump very large, abrupt ; palpi black, an- 

 tennae black ; two basal joints grayish ; antennae of the male 

 three or four times longer than the body ; the third joint, if bent 

 backwards, would reach beyond the root of the wing ; every 

 following joint is longer than the preceding ; the sixth joint as 

 long as the fourth and fifth together ; the spines on the lower 



