BY FREDERICK A. A. SKUSE. 819 



p. 273, 1856 ; Schiner, R A. Dipt. II., 1864 ; O.-Sacken, Proc. 

 Acad. Nat. Sc. Philad. p. 225, 1859 ; Mon. Dipt. N. Amer. lY. 

 p. 146, 1869; Studies, II. p. 193, 1887. 



*' Two sub-marginal cells ; four posterior cells ; discal cell present 

 .or absent. Wings pubescent along the veins only. The second 

 longitudinal vein usually originates at a very acute angle, some 

 distance before the middle of the anterior margin ; the sub-costal 

 cross-vein is at a considerable distance (two or three lengths of 

 the great cross- vein, or more) from the tip of the auxiliary vein ; 

 the prsef urea ends in the second sub-marginal cell, which is longer 

 than the first. Antennae 16-jointed. Tibise without spurs at the 

 tip ; ungues smooth on the underside \ empodia distinct." (Osten- 

 Sacken). 



Sub-genus Erioptera, O.-Sacken. 



A. The '^ praef urea ends in the second sub-marginal 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 ijosterior branch of the fourth longitudinal vein is forked 



(in other words, when the discal cell is open, it coalesces 



with the second posterior cell ; when it is closed, the inner 



end of the third posterior cell is nearer the basis of the 



wing than the inner end of the second). 



a. The seventh longitudinal vein is arcuated (converging 



towards the sixth) in such a manner, that the auxiliary 



cell is broader in the middle than near the margin of the 



wing." (Osten-Sacken). 



340. Erioptera ochracea, sp.n. 



(J. — Length of antennae ... 0'030 inch ... 0.76 millimetres. 



Expanse of wings 0-170 x 0-042 ... 4-31 x 1-06 



Size of body 0-135x0-020 ... 3-42x0-50 



