22 BULLETIN 123, UNITED STATES NATIONAL MUSEUM. 



KEY TO THE SPECIES OF PBTKOVA. 



1. Ground color of fore wing from base to apex orange yellow or ferruginous 



brown 2 



Ground color of fore wing gray or brown heavily dusted with black ; if 

 ferruginous or yellowish with at least a grayish basal area 6 



2. Fore wing orange yellow with two white fascia (7) sabiniana. 



Fore wing ferruginous abundantly streaked with white 3 



3. Head snow white; thorax and extreme base of fore wing heavily marked 



with white; a broad median fascia of silver white (1) comstockiana. 



Head cream white or ferruginous ; thorax and extreme base of fore wing 

 showing more of the ferruginous ground color than of white scaling; 

 median whitish cross markings interspaced with ground color 4 



4. Fore wing with no black scaling on disk; basal line of cilia ferruginous; 



hind wing whitish shading to pale ochreous (2) virginiana. 



Fore wing with scattered dustings of black scales on disk; basal line of 

 cilia black; hind wing dark smoky fuscous 5 



5. Head cream white (3) albicapitana. 



Head ferruginous ochreous (4) var. arizonensis. 



6. Apical area of wing reddish or ferruginous ochreous 7 



Apical area of wing grayish, blackish, or brown dusted with black 9 



7. Termen of fore wing edged with a fine black line at base of cilia. 



(8) edemoidana. 

 Termen not so margined 8 



8. Fore wing with distinct grayish median fascia slanting outwardly from dor- 



sum to costa; termen broadly margined with dark brick red__(9) zozana. 



Fore wing with no such median fascia ; termen with a narrow red marginal 



line (10) monophylliana. 



9. Ground color of fore wing brown dusted with black and with pale markings 



more or less overlaid with metallic scales 10 



Ground color gray or grayish white ; no metallic scaling on fore wing 11 



10. Thorax sordid white dusted with grayish fuscous (5) metallica. 



Thorax pure white (6) luculentana. 



11. Head ferruginous ochreous ; fore wing with a distinct black spot on dorsum 



before anal angle and a large black half moon spot on termen near apex ; 



also several faint scattered blotches of greenish scales (13) picicolana. 



Head dark grayish fuscous; fore wing blotched with white or irregularly 

 barred with grayish white 12 



12. Pale markings on fore wing pure white and fused into two irregular 



blotches forming tortuous anti-median and post median fasciae. 



(12) burkeana. 



Pale markings sordid gray white, barring wing from base to termen and 



interlined and spaced with the grayish fuscous ground color; not fusing 



in conspicuous blotches (11) gemistrigulana. 



1. PETROVA COMSTOCKIANA (Femald). 



(Figs. 20, 54.) 



Retinia ? comstockiana Feknald, Can. Ent., vol. 11, 1879, p. 157. — Comstock, 

 Kept. Dept. Agr. for 1879, 1880, p. 235.— Packard, Fifth Report U. S. But. 

 Com., 1890, p. 742. 



Evetria constoclciana Fernald, in Dyar List N. Amer. Lepid., no. 5000, 1903. — 

 Baenes and McDunnough, Check List Lepid. Bor. Amer., no. 6762, 1917. 



