LEPIDOPTERA 



667 



ing veinRi (Figs. 823 and 824). 

 In the hind wings in most of 

 the genera veins Sc+Ri and 

 Rs coalesce to or beyond the 

 middle of the discal cell or with 

 a short fusion near the end of 

 the discal cell (Fig. 823); but 

 in certain genera, where the 

 costal area of the hind wings is 

 greatly expanded, these veins 

 extend distinctly separate from 

 each other, except that they 

 are connected by the free part 

 of vein Ri near the middle of 

 the discal cell (Fig. 824). In 

 a few genera belonging to other 

 subfamilies veins Sc+Ri and 

 Rg of the hind wings coalesce 

 to the middle of the discal cell, 

 but these genera lack the ac- 

 cessory cell in the fore wings 

 characteristic of this subfamily. 

 This subfamily ranks sec- 

 ond in size among the geom- 

 etrid subfamilies, including 

 365 North American species; 

 these represent 58 genera. 



Many of the species are very common ; among them are the following. 

 The white-striped 



black, Trichodezia al- 



b V itt dta. — This 



beautiful little moth, 



which occurs from 



the Atlantic to the 



Pacific, is the most 



easily recognized 

 member of the family. It expands 

 about 22 mm. and is of a uniform black 

 color, with a single, very broad white 

 band extending across the fore wing from 

 the middle of the costa to the inner angle, 

 where it is usually forked. The fringe of 

 the wings is white at the apical and inner 

 angles of both pairs; sometimes the 

 white is lacking on the inner angle of the 

 hind wings. The early stages are un- 

 known. 



The bad-wing, Dyspteris ahortivdria. 

 — It is easy to recognize this moth (Fig. 

 825) by the peculiar shape of its wings, 



Fig. 821. — Wings of Acidalia enucleata. 



Fig. 822. — Hcema- 

 to pis grataria. 



Fig. 823.- 

 mendica. 



-Wings of Eudule 



