484 WILLIAM T. M. FORBES 



This form is doubtfully distinct from boscana Fabricius of Europe, which is not 

 close to our so-called boscana (placidana Robinson). Larva fastening together 

 two overlapping leaves of white birch, living in a small white tube. Pale dull 

 green; head and cervical shield black; also with blackish prespiracular and sub- 

 ventral warts on prothorax. 



This may be merely a gray winter form of P. niveana. 



Montreal to New Jersey and western Pennsylvania. New York: Big Indian 

 Valley, Bronx (New York City), Staten Island, Long Island. 



8. P. niveana Fabricius. Pure white, with a few gray scales; the tufting as in 

 /'. trisignana, but interrupted in cell Cu^ 20 mm. 



Larva on birch. 



Europe; reported from Ontario. 



9. P. nigrolinea Robinson. White, irregularly dusted with gray, often gathering 

 into spots at middle of wing; typically, but not usually with a fine black longi- 

 tudinal line from base to middle of wing. Tufts numerous, the outer ones forming 

 parts of three series; the median series strongly broken at Cu,, and less so at Cu 2 . 

 25 mm. 



This form is very probably a mere variant of P. trisignana. 



Montreal, Quebec, to western Pennsylvania, Missouri, and British Columbia. 



10. P. chalybeana Fernald. Tufts somewhat reduced, with wider spaces between 

 them, but with the one in cell CUj in line with the others. Costa not so roughly 

 scaled as in P. hastiana. Dull gray, normally with darker shades, especially with 

 traces of the costal triangle ; sometimes with costal triangle well-marked, and a 

 heavy blackish patch at base of inner margin. Tufts often defined with black. 

 22 mm. 



August; October to May. 



Maine to western Pennsylvania. New York: Ithaca, McLean. 



11. P. comandrana Fernald. Tufts almost obsolete. Pale brown, with obscure 

 striation and a darker terminal line; costal patch normally strongly contrasting, 

 dark brown, with central triangle of the ground color, rarely suffused and broken 

 up. 13 mm. 



June; November. Larva on Comandra bellardi; light green with whitish pro- 

 tuberances, and black head and cervical shield; in early June. 

 Massachusetts to Texas. 



12. P. americana Fernald. Head reddish white. Fore wing white, reticulate 

 with bright brown, the transverse bars of the reticulation much stronger than the 

 veining, which is only partly traceable. Costal triangle bright brown, slightly 

 suffused below, with pale center; fringe deep brown at base, yellow-brown out- 

 wardly, contrasting. Hind wing mouse gray. 15 mm. 



October. 



Ontario and New Hampshire to western Pennsylvania. 



13. P. nivisellana Walsingham. Light gray; costal part toward base and a 

 shade about the contrasting black triangle white; apex coppery orange, with a 

 couple of black spots. Five large transverse tufts of whitish scales and several 

 small ones, partly black. Markings variable in extent but unusually constant for 

 the genus. 15 mm. 



Larva on Cratsegus. 



Generally distributed, west to British Columbia and south to Pennsylvania. New 

 York : Ithaca. 



14. P. variegana Schiffermuller. Head grayish or black, contrasting with the 

 white thorax; fore wing white or yellow at base; typically, with the antemedian 

 tuft below cell blackish, and the area between it and the inner margin gray; in 

 the only specimen seen from this region, nearly solid white. Outer half of wing 

 contrastingly dark, yellowish to nearly black. 13 mm. 



July; larva on various trees and shrubs. 

 British Columbia; Europe. New York: Clinton. 



