NORTH AMERICAN LEPIDOPTERA. 181 



twice as long and stout as the anterior ; median tibia with a single 

 I)air of unequal s})urs at tip ; posterior with two pairs of hjnger, un- 

 equal spurs. Anterior tarsi with a row of stout, curved spines out- 

 wardly, most prominent in lineata. 



Primaries with eleven veins, the cell short ; outei- margin arcuate, 

 entire, oblique; apex acute; hind margin very little sinuate. Prof. 

 Feruald says the primaries have sometimes twelve veins ; none of 

 the specimens examined by me had more than eleven, but it is not 

 unlikely that 9 does occasionally branch ; in such case vein 10 must 

 be very difficult to see, except by fully denuding the wing. Secon- 

 daries with 2, o and 4 nearly equidistant at base ; 5 midwa^' from 

 the cross-vein. The margin is entire, except for a slight projection 

 on vein lb. 



The genitalia of the male have the supra-anal plate produced into 

 a short, abruptly pointed and slightly curved hook ; the inferior pro- 

 jection nearly as long as the superior, but thicker, the tips l)lunt. 

 Side pieces enlarging somewhat toward tip, then rather suddenly 

 rounded off, the ,angle rather inferiorly. From the inferior margin 

 near the base arises a single corneous hook, differing somewhat in 

 form in the two species. 



The European fauna is rich in forms in this genus, while in 

 America but tAvo species are found. They have a habitus all their 

 own, and are consequently recognizable at a glance whenever a sin- 

 gle typical form has been once carefully observed. 



T'wo species are known from our fauna, one of which is claimed 

 as identical with European forms, viz., chaimenerii with gaUil. This 

 question will be more fully discussed hereafter. 



ClutmcBnerii has the spinules of tibia less marked, the abdomen 

 more abruptly conic, the thorax immaculate on disc, the veins of 

 primaries not white lined. 



Lineata has the tarsal armature much heavier, the abdomen more 

 elongate, the thorax Avith longitudinal white lines ; primaries with 

 veins white, marked. 



D. gallii Eott. Naturf. vii, 107 ; Wlk., C. B. M. Lep. Het. viii, 16G ; Clem.,* 

 Journ. Ac. N. Sci. Phil. iv. 1859, 144; Bd., Lep. Cal. 66; G. <fc E., Pr. E. S. 

 Ph. V. 1.56; Tr. A. E. Soc. ii, 75; Strk., Lep. Rhop. et Hot. 79; Bd., Sji. Gen. 

 Het. i, 169 ; Butl., Tr. Zool. Soe. Lond. ix, 569. 



chameenerii Harr.,* Sill. Journ. 36, .305, Deilephila ; Ag., Lake Superior, 387. 

 pi. vii, fig. 2; Wlk., C. B. M. Lep. Het. viii, 167 = gallii; Morr.,* Syu. 1862, 

 165, DeilepMln : Harr., luj. Ins. 3-28; Lint.,* Pr. E. S. Ph. iii. 660, Deilephila; 



