PTEROPHORUS. 39 



extending, with their cilia, nearly 3 millims. 

 beyond the apex of the abdomen, the upper one 

 being less than half the length of the others, 

 but fringed with a double brush of long, pale 

 ochreous, hair-like scales. 



VAR. f3. The head and fore wings pale ochreous ; the 

 costa even paler, the spots scarcely indicated. 



Expanse 26 millims. 



Several specimens obtained through Colusa, Shasta, 

 and Siskiyou Counties, California, in July and August 

 1871, show various modifications of colouring. The 

 darkest varieties occurred on Pit River, the palest 

 about 60 miles to the south, at a few days' interval ; 

 but having met with almost every possible inter- 

 mediate gradation, I must conclude that they belong 

 to one and the same species. I have one bred speci- 

 men of the intermediate form, the larva having been 

 reared on leaves of a species of sunflower. 



PTEROPHORUS, WaUetyrtn. 



Pterophorus monodactylus, Linn. 



(PLATE II. FlG. 16 AND PLATE ILL FlG. 1.) 



Pterophorus monodactylus, Linn., Wocke, Cat. 3167. 



Pterophorus pergmcilidactylus, Packard, Ann. Lye. Xat. Hist. N. Y. 



x. p. 266. 

 Pterophorus cinercidactylus, Fitch, Xox. Ins. N. Y., Reps. 1 & 2, 



p. 144. 



