GENUS BRENTHIS 143 



Strecker cut that line he divorced Arge from Eurynotne forever. 

 Arge, therefore, is a form of Montivaga, "for which it is some- 

 times mistaken." The color of underside of hind wing is 

 flesh-red. 



144. Argynnis Erinna. Not elsewhere illustrated. 

 Plate XVII ; Figures 144, a, b. 



Fig. 144, Male, Summit, Cal., 7,500 feet altitude, July, 

 1892; Author. 



a, Male, underside. Summit, Cal., 7,500 feet alti- 



tude, July, 1892; Author. 



b, Female, Summit, Cal. 7,500 feet altitude, July, 



1892 ; Author. 

 This is a mountain butterfly, like the two preceding and the 

 following species, and inhabits the same range of mountains. The 

 characters of Erinna, as compared with its allies, are smaller size, 

 deeper color, base of wings darker, black markings more heavy, 

 and on underside of hind wing the spots are buffy and unsilvered, 

 with the band scarcely less paler than the disk. 



145. Argynnis Egleis. 



Plate XVII ; Figures 145, a, b. c. 



Fig. 145, Male, Truckee, Cal., June, 1886; Author. 



a. Male, underside, Truckee, Cal., June, 1886; 



Author. 



b. Female, Donner Lake, Cal., June, 1886; Author. 



c. Female, underside, Truckee, Cal., June, 1886; 



Author. 

 Similar to the preceding ; a trifle larger in size, with the colora- 

 tion similar to Arge ; on underside the flesh-red of Arge is re- 

 placed with brownish or yellowish ; the marginal lunules of the 

 female are silvered, but usually no others are silvered in either sex, 

 but are palest buff. In the Plate the pair of undersides shows 

 effectually the variation of colors in the sexes. 



Genus BRENTHIS. 



This genus is composed of six species belonging to our fauna, 

 all of them rather small in size, and all very similar in appearance 

 and in size. The aspect of the group is somewhat like that of 



