1936 ] 
The Persius Group of Thanaos 
113 
men from Arizona in coll. Townes has the same size and 
genitalia, and some of the brassy iridescence, but is much 
overlaid with white. It is certainly not persius or afranius. 
There are two broods, in May and July, but spring speci- 
mens seem rare. 
Thanaos avinoffi Holland 
1930. Thanaos avinoffi Holland, Ann. Carn. Mus. xix (3), 
156. 
1931. Thanaos avinoffi Holland, Butt. Book (Revised 
Ed.), 352, pi. li, figs. 28, 29. 
1931. Erynnis avinoffi Lindsey, Bell and Williams, 
Denison Univ. Bull., Jour. Sci. Labs, xxvi, 62. 
I have examined this only superficially but believe it a 
race of persius , whose food, willow, is a common species 
in the far north. A superficial examination of T. proper - 
tuis var. borealis Cary, from the Canadian Northwest, in- 
clines me to believe it is also a persius- strain, and transi- 
tional to avinoffi. 
