326 



twelve are said to live together, and different stages may be found 

 in one group. The pupal instar lasts one week. Riley apparently did 

 not learn the stage of hibernation, and we are unable to supply this 

 information. He describes the larva and pupa as follows: 



"Larva. — Average length 0.60. Largest in the middle of body, tapering 

 thence each way. Color light straw-yellow — greener when young. Somewhat 

 darker, partly translucent, dorsal, subdorsal and stigmata! lines. Two lateral 

 rows of black spots, the lower spots rather smaller and placed behind the upper 

 ones. A third row above these, and others along the back, but so small that 

 they are generally imperceptible with the naked eye, except on the thoracic 

 segments, being especially distinct on segment 2. Head small, black, sometimes 

 inclining to brown. Cervical shield black, divided longitudinally in the middle 

 by a higher line. Caudal plate also black. Segment 11, besides the spots above 

 mentioned, has two transverse black marks, the posterior one the largest. 

 Thoracic legs black, the others of the same color as the body." 



"Pupa. — Average length 0.45.— Soft, dull yellow, with a lateral dusky line, 

 each side of dorsum, and another, less distinct each side of venter. Also dusky 

 about the head and wing-sheaths." 



From two voided pupal skins we are able to add that the pupa 

 is much less angular and rather stouter than that of punctidactyla 

 already described. The dorsal ridges are present, but very low, and 

 the leaf-like projections and tubercles are not at all developed. The 

 cases of the appendages form a very short ventral process. 



We have had much difficulty in deciding whether or not this and 

 the following species are distinct, and have come to the conclusion 

 that they probably are. The differences are mentioned under percno- 

 dactyla. The types of hesperis Grinnell belong to carduidactyla ac- 

 cording to our concept. 



9. Platyptilia I'ERCNODACTYLA Walsitigham. PI. XLIII, fig. 2. PI. 

 L, fig. 14. 



Platyptilns percnodactyhis VValsingham, Pter. Cal. Ore. 8, pi. I, f. 7, 18S0. 

 XPlatyptUia percnodactyla Femald, Smith's List Lep. N. A. 87, 1891. 



Id., Pter. N. A. 27, pi. VIII, ff. 14, IS, 1898. 



Id., Bull. 52 U. S. N. M. 443, 1902. 



Anderson, Cat. B. C. Lep. 50, 1904. 



B. C. Ent. Soc. Check List 42, 1906. 



Meyrick, Gen. Ins. C, 11, 1910. 



Id., Wagner's Lep. Cat. pars 17, 14, 1913. 



Barnes & McDunnough, Check List 150, 1917. 



The appearance of this species is substantially that of the preced- 

 ing, and for a time we regarded them as the same. We have con- 



