THYRETJS. 15 1 



Pupation. The transformation of the larva takes place in a 

 superficial cell. The pupa is dark-brown; the head case broad 

 and rounded; the tongue case not apparent, and level with the 

 breast. There is, I think, but one annual brood. The larva 

 reaches its development about the latter part of July, and enters 

 the pupa state to appear in the following spring as an imago. 



Food-plants. The indigenous and cultivated grape-vines, and 

 Ampelopsis quinquefolia. 



New York; Pennsylvania; Georgia; Massachusetts; Ohio. 



Clemens. 



Group II. 



The thorax tapers on the sides markedly to the head, which is 

 small and prominent. The front is smooth and narrow, the eyes 

 very small, the palpi acutely haired at the extremity, and exceed- 

 ing the front, the antennae with a moderate hook without seta; the 

 tongue extends to about the third abdominal ring. The tip of the 

 anterior wings is rounded, the hind margin circularly excavated 

 beneath tip, and above the inner angle, the middle being cotrvex. 

 Posterior wings, hind margin scarcely denticulated, and slightly 

 excavated near the inner angle. 



2. T. nessus. Figured in Cram. pi. 107. Walker, C. B. M. p. 99. 



The head, palpi, and thorax, dull ferruginous brown, palpi be- 

 neath and breast rufescent; a yellowish-white streak on the sides 

 of the head and thorax, and a transverse ferruginous line on the 

 hind part of metathorax. The abdomen a dark chestnut-brown, 

 with the hind margins of fourth, or fourth and fifth segments, pale 

 yellow, with three or four bright ferruginous, lateral spots, begin- 

 ning on the fourth segment, and two very small pure white tufts 

 on the segments adjacent to the triple apical tuft, which is deep 

 chestnut ; beneath rufescent, with three lateral white dots on the 

 hind portions of the posterior segments. Anterior wings brown, 

 with a purplish hue, costa grayish-brown ; an indistinct dark-brown 

 band and line in basilar space ; a dark chestnut, broad median 

 band, divided above the medio-superior nervule to the costa, and 

 containing a lighter colored discal spot ; a grayish-brown subter- 

 minal line interrupted by the central nervules, and edged anteriorly 



