51 



Early stages and food plant unknown. 



Described from seven examples taken in September, in Placer 

 County, California, and presented to the National Museum by the 

 late Dr. C. V. Riley, to whose memory I dedicate this species. 



PTEROPHORUS MONODACTYLUS. 



Alucita monodactyla Linn., Syst. Nat., Ed. X., Vol. I., p 542 (1758). 

 Pterophorus cineridactylus Fitch, N. Y. Rep., Vol. I., p. 848 



(1854). 



Pterophorus ncevosidactylus Fitch, N. Y. Rep., Vol. I., p 849 (1854) . 

 Pterophorus pergracilidactylus Pack., Ann. Lye. N. Y., Vol. X., 



p. 265 (1873). 

 Pterophorus monodactylus Wlsm., Pter. Cal. and Ore., p. 39, Plate 



II., fig. 16 ; Plate in., fig. 1 (1880). 



Expanse of wings, 22-26 mm. Head and thorax pale gray, 

 sprinkled with brown scales. Palpi short, tipped with brown; 

 autennre grayish white, spotted with fuscous above. Abdomen 

 grayish ochreous, striped with fuscous and brown scales on the 

 sides ; a dorsal row of brown dots, one at the base of each seg- 

 ment. Legs grayish, with the joints enlarged and covered with 

 brownish hairs ; a tuft of scales near the middle of the hind tarsi 

 on the side opposite the spurs. 



Fore wings varying from pale grayish to pale reddish brown, 

 often mixed with white and sometimes with a few black scales ; 

 stripes or streaks of dark brown or blackish scales on the costa 

 "and hind margin; before the fissure a brown spot, sometimes 

 tapering to a point toward the base ; an elongated spot of brown 

 scales on the costa, half-way between the latter and the apex, with 

 two smaller ones between it and the apex ; one or more small 

 blackish dots on one or both lobes near the apex. Fringes gray- 

 ish, tinged with fuscous on the outer third of fissure. Hind wings 

 gray or fuscous, with a silky lustre ; fringes slightly darker. 



This species is exceedingly variable both in color and markings, 

 some examples being very light with but few spots, while others 

 are reddish brown. 



Habitat. Europe ; Maine to California. Food, Convolvulus se- 

 ptum. Convolvulus arvensis, Chenopodium album, Atriplex patula. 



" Larva. Length, when at rest, about five-eighths of an inch, 

 and stout in proportion. Head polished and rather small, nar- 

 rower than the second segment. Body uniform and cylindrical, 

 tapering a little posteriorly. Segmental divisions well defined and 

 deeply cut ventrally ; each tubercle emits a tuft of short but rather 

 strong hairs. Ground color bright yellowish green, more decid- 



