ERIOPTERA. 155 



Description of the species. 



A. The prsefurca ends in the second submarginal cell, which is longer 

 than the first ; the inner end of the discal cell (or, when it is 

 open, of the cell with which it coalesces) is on the same line with 

 the small cross-vein. 

 1. The posterior branch of the fourth longitudinal vein is forked. 



a. Seventh longitudinal vein arcuated, converging towards the 

 sixth (Tab. I, fig. 16) : subgenus Erioptera (compare 

 above, page 151). 



1. E. septemtrionis 0. S. % and 9.— Fuscano-ochracea, alis irn- 

 maculatis, venarum villosie perbrevi, halteres capitulo infuscato. 



Brownish-ochraceous, wings immaculate, the pubescence of the veins very 

 short, the knob of the halteres brown. Long. corp. 0.2 — 0.25. 



Syn. Erioptera septemtrionis 0. Sacken, Proc. Ac. Nat. Sc. Phil. 1859, p. 226. 



Body ochraceous, more or less tinged with brownish ; front 

 infuscated in the middle ; palpi brown ; antennas brownish, more 

 or less pale at the basis ; thorax brownish above, with more or 

 less sulphur yellow in the humeral region ; a brown stripe, more 

 or less distinct, along the middle of the mesonotum and of the 

 collare ; pleurae usually pale, with a brown stripe, running from 

 the collare to the root of the halteres ; in some specimens, the 

 pleurae are brownish ; knob of the halteres dark brown ; feet 

 brownish -yellow; abdomen brownish above, venter paler. Wings 

 immaculate ; veins brownish, their pubescence very short, not 

 long enough by far to reach from vein to vein and thus to cover 

 the surface of the cells. 



Hob. Maine (Packard) ; Sharon Springs, K Y. ; seems to be 

 more common in the north. I possess a male from Washington, 

 D. C, which is altogether brownish, humeri yellowish, forceps 

 reddish ; a female of very large size (locality uncertain) has the 

 same dark coloring. I believe that they belong to E. septem- 

 trionis, which can always be distinguished by the dark knob of 

 the halteres and the short pubescence of the wings. 



2. E. Tillosa 0. S. % . — Fusca, alis fuscescentibus, conspicue fusco- 

 villosulis, halteribus flavis. 



Brown, wings brownish, with conspicuous brown hairs ; halteres yellow, 



Long. corp. 0.25. 

 Syn. Erioptera villosa 0. Sacken, Proc. Ac. Nat. Sc. Phil. 1859, p. 226 



