This butterfly is circumpolar, being found in Norway, Lapland, northern Russia, and Siberia, through Alaska, British America, and Labrador, occurring also upon the highest peaks of the Rocky Mountains as far south as Colorado.
(8) =Brenthis polaris=, Boisduval, Plate XV, Fig. 11, ♂; Fig. 12, ♂, _under side_ (The Polar Fritillary).
_Butterfly._--The upper side dull fulvous; the markings on the inner half of the wings are confluent, and lost in the brownish vestiture which obscures this portion of the wing. The outer median area is defined by irregular zigzag spots which flow together. Beyond these the submarginal row of small black spots stands out distinctly upon the lighter ground-color of the wings. The outer margin is marked by black spots at the end of the nervules, on the fore wings somewhat widely separated, on the hind wings narrowly separated by the lighter ground-color. On the under side the wings are fulvous, with a marginal row of white checkerings on both wings. The hind wing is deeply mottled with ferruginous, on which the lighter white markings stand forth very conspicuously. Expanse, ♂, 1.50 inch.; ♀, 1.50-2.00 inches.
This butterfly has been found in Labrador, Greenland, and other portions of arctic America, as far north as latitude 81° 52´.
(9) =Brenthis frigga=, Thunberg, Plate XV, Fig. 13, ♂; Fig. 14, ♀, _lower side_ (Frigga).
_Butterfly_, ♂.--On the upper side this butterfly somewhat closely resembles _polaris_, but the markings are not so compact--more diffuse. The fore wings at the base and the hind wings on the inner two thirds are heavily obscured with brown. The outer margins are more heavily shaded with blackish-brown than in _B. polaris_. On the under side the wings are quite differently marked. The fore wings are fulvous, shaded with brown at the tips, and marked with light yellow on the interspaces beyond the end of the cell. The hind wings are dark ferruginous, shading into purplish-gray on the outer margin, with a whitish quadrate spot on the costa near the base, marked with two dark spots, and a bar of pale, somewhat obscured spots, forming an irregular band across the middle of the hind wings.
♀.--The female does not differ greatly from the male, except that the spots on the under side of the hind wings stand forth more conspicuously, being lighter in color and better defined. Expanse, 1.65-2.00 inches.