Entomology of the Illinois River. 183 



segments 4-7 similar but smaller; that on segment 8 

 closed up, forming a rounded tubercle. Last segment 

 darker and rougher, flattened, about as broad as long, 

 shield-shaped, with a broad truncate apex; base more 

 convex above; sides with a sharp margin, rather nar- 

 rowly deflexed; beneath, it is longitudinally sulcale each 

 side; at its apex is a bundle of thick chitinous fila- 

 ments, whose tips are curled up outwardly and which 

 enable the pupa to attach itself firmly to the silk of the 

 cocoon. 



Imago. — Ochre-brown to ochre-buff, abdomen and hind 

 wings paler. Ocelli present; maxillary palpi porrect; eye 

 bordered above with white scales. Fore wings moderately 

 narrow and slightly rounded at tip, not pointed; lines 

 obscure, but not obliterated as in genitalis. Anterior 

 transverse line waved, crossing wing at basal third; a 

 dark point in the cell; exterior to this a small pale spot 

 bordered outwardly by a distinct short transverse 

 dash ; a brown shade across the end of the cell ; posterior 

 transverse line nearly parallel to outer margin, angula- 

 ted on the veins, very deeply but narrowl,v indented on 

 vein VII 2*, aud about half as much on vein IX; bordered 

 with paler ochre within at middle; the space between this 

 line and the outer edge also somewhat paler, through 

 the middle of which runs the obscure zigzag subterminal 

 line, more or less broken up into chevron-t-haped marks. 

 Terminal line nearly or quite wanting. Hind wings pale 

 whitish or yellowish ochre, a brown discal dot, often 

 indistinct, and at the distal third a short transverse 

 fuscous arc, present in all the specimens; a fine wavy 

 marginal line often present. Beneath whitish with o- 

 chrey tint, the dorsal markings vaguely i-epeated in light 

 brownish, except on posterior part of fore wings. Body 

 beneath, and middle and hind legs white. Unusually 

 variable in size; expanse 22-35 mm., body 10-15 mm. 



* Comstock's nomenclature. ("Manual for the Study of Insects.") 



