325 



Pterophorus cardui Riley, Index to Mo. Rept. 83, 1881. 



tPlaiyptilia cardiiidactyla Fcmald, Smith's List Lep. N. A. 87, 1891. 



Id., Pter. N, A. 26, pi. II, ff. 1, 2; pi. VII, ff. 8-11, 1898. 



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



Dyar, Proc. U. S. N. M. XXVII, 923. 1904. 



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



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



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



Winn, List Ins. Que. 85, 1912. 



Meyrick, Wagner's Lep. Cat. pars 17, 13, 1913. 



Barnes & McDunnough, Check List 150, 1917. 

 PlatyptiUa hesperis Grinnell, Can. Ent. XL, 316, 1908. 



Meyrick, Wagner's Lep. Cat. pars 17, 15, 1913, 



Barnes & McDunnough, Check List 150, 1917. 

 Brownish buff, thorax whitish behind. Antennae dotted with brown above. 

 Frontal tuft moderate, blunt, surpassed by third joint of oblique palpi. Front 

 and middle legs brownish inside, dark without, the tarsi distinctly pale. Hind 

 tibiae with two broad brown bands ; tarsi with at least the second joint entirely 

 whitish. 



Primaries with the costa dark brown dotted with white as far as the usual 

 brown triangle, which is much the darkest part of the wing. Disk with blotches 

 near inner margin at about one-fourth and three-fifths from base, and a spot 

 in cell. The heavy triangle contains a dark transverse dash before cleft which 

 is visible only in paler specimens. Beyond triangle there is a transverse line 

 of ground color, often obsolete except on costa; both lobes thence pale brown, 

 crossed by a vague light Hne toward outer margin ; terminal area usually with 

 some hoary scales. Fringes grayish-buff with a row of brown scales in base 

 along outer margin, gray tufts at apices and anal angles, and two dark brown 

 scale tufts on inner margin. Apex acute, moderately produced. Secondaries 

 gray-brown, fringes slightly paler with short dark scales at apices of first two 

 lobes. Fringes of inner margin of third lobe with a prominent triangular 

 tooth of dark brown scales at middle, its point perhaps slightly before middle 

 of lobe. This tooth is preceded and followed by a variably complete row of 

 short, dark scales, and the lobe is whitish before it. Expanse 20-27 mm. 



The species varies to a duller brown, sometimes with a purplish tinge, 

 and reduced contrasts. Darker specimens show some superficial whitish ves- 

 titure. 



Male genitalia as in pcrcnodactyla Wlsm. (see plate L, fig. 14). 

 Distribution: Laborador (Aug.) to D. C. (May), west to the 

 Pacific Coast. We have it from various localities taken in every 

 month from May to September, inclusive. 



Riley, in his initial paper on the species, gives an interesting 

 account of the early stages. According to this account the larvae 

 are gregarious, living in webbed heads of common thistles. Eight to 



