148 LEPIDOPTERA OF NORTH AMERICA. 



twice as long as the thorax. The wings are transparent in the 

 middle; the fore wings with the hind margin entire, obliquely 

 convex, and the inner margin concave beyond the inner angle ; 

 hind wings somewhat acuminated at the tip and short. The legs 

 are slender and the hind tibiae with four moderate spurs. Male, 

 antennae finely ciliferous. Female, nearly simple. 



The larva tapers anteriorly, has a dorsal and stigmatical stripe, 

 and a short recurved horn. It undergoes its transformation in an 

 imperfect cocoon on the surface of the ground. 



1. S. difiinis Boisd. S. fusiformis Abbot & Smith. Figured in Sm. Abb. 

 I, pi. 43. Boisd. sp. gen. pi. 15. 



Head and thorax pale yellowish-green ; palpi blackish terminally 

 and pale yellow beneath ; breast pale yellow, with blackish hairs 

 beneath the legs, and all the legs black. The abdomen adjoining 

 the thorax has the thoracic hue ; the third and fourth segments, 

 sometimes only the fourth, are black or blackish along the sides of 

 the four first anterior rings, and the fifth and sixth are pale brown- 

 ish mixed with yellow. The ventral surface is bluish-black, with 

 pale yellow patches corresponding to the tufts on the margins of 

 the fifth and sixth segments. The lateral anal tufts are black, the 

 central pale brown. The disk of the anterior wings is transparent 

 almost to the base, with a narrow, dark brownish border along the 

 costa, a patch on the inner margin tapering to the inner angle, and 

 a narrow terminal border in the <£ , but rather broad and dentate 

 between the nervules in the ? , of the same hue ; a ferruginous 

 patch on the apical interspace, sometimes followed by a smaller 

 one in the succeeding, in the 9 . The posterior wings are bordered 

 with dark brown on the costa near the base, broadly on the inner 

 margin, the terminal margin in the J" very narrow, and moderate 

 in the ?. 



There are variations in color ; sometimes the thorax is fawn- 

 colored above and somewhat ochreous beneath : the abdomen fawn- 

 colored at the base, the two middle segments dark reddish-brown, 

 the ends and sides blackish and the two terminal rings fawn-color 

 above, with two large yellow patches on the ventral surface which 

 is black. 



