NORTH AMERICAN LEPIDOPTERA. 105 



A series of specimens examined by me shows very little variation. 

 Except in the smaller size and consequent smaller vitreous spaces I 

 could distinguish no difference from luiiformis. 



Mr. Lintner has given us a very good life history of this species 

 in the Ent. Cont. ii, 112, which I reproduce in nearly his own words 

 for comparison with the description of H. thysbe: 



Egg on V'ibnrnnm opulns (Snow ball) in August; nearly round, smooth and of a 

 pale green color. 



Young larva of a uniform whitish green, with a straight, dark brown caudal 

 horn. The first moult occurred August 24th ; length .15 inch, of a uniform pale 

 green. Body under a lens showing a number of delicate hairs. Caudal horn 

 brown, smooth and straight. When ready for the change it was .32 inch, in 

 length. Second moult August 30th; length .35 inch, in length. Head uniform 

 pale green, with short, fine whitish hairs. Body slightly hairy, pale green, with 

 a lateral stripe of yellow green ; segments with a yellow green dot in front on 

 each side of the vascular line and a few smaller ones on the posterior half. Cau- 

 dal horn straight, nearly cylindrical, light red, striped anteriorly near the base 

 and tipped with brown, and spotted with brown intermediately; borne at an 

 angle of about 40°. Third moult six days later; length .5 iucli. Head granu- 

 lated. Collar bordered anteriorly with about twelve small tubercles. Body 

 minutely papillose, else as before. Caudal horn light red, regularly tapering 

 from base to tip, covered with spinules which anteriorly and posteriorly have 

 black bases. Stigmata deep orange, with a yellow green dot at each end ; those 

 of the prolegs bearing segments bordered before with a deep orange line. Legs 

 at base marked with black ; prolegs on the outer side and body beneath on the 

 last two segments pale red. Fourth moult sixth days later; length .(35 inch. 

 Head green, its surface appearing shagreened under a lens, marked with indis- 

 tinct lateral stripes and dotted with whitish granulations which diminish in size 

 toward the centre ; mandibles yellow, black tipped ; eyes on a fuscous crescent. 

 Collar with whitish granulations, except on the anterior margin, where they are 

 orange. Body greenish white dorsally, with a vascular line of rose pink inter- 

 rupted at the incisures; a lateral stripe of yellow green papillae of one to each 

 annulet, edged above with darker green and below with green shading deeper to 

 the prolegs; lateral papillae greenish yellow; ventrally, from the fourth segment 

 to the posterior extremity, concolorous with the vascular stripe. Caudal horn 

 curved, rose colored, tipped with ferruginous, with fuscous spinules anteriorly 

 and posteriorly. Stigmata crimson, white dotted at the extremities and sur- 

 rounded with rose. Legs and prolegs ferruginous basally, next fuscous and 

 rufous terminally. As the larva approaches maturity it becomes more white 

 dorsally, the red of the vascular stripe changes to white and the red surrounding 

 the .stigmata disappears. With the distension of the skin the papillae change to 

 whitish ocellations. 



The larva makes a slight cocoon of bronze brown silk, so loose 

 that the pupa is visible through the meshes. The pupa is of a 

 chestnut color with testaceous at the incisures. The imagos emerged 

 in April and had the "vitreous spot" of each wing thinly covered 

 with scales. 



TKANS. AMER. KNT. SOC. XV. (14) JUNE, 1888. 



