Butterfly.—The wings are pale fulvous, the fore wings at the base and the hind wings on the inner half being deeply obscured with fuscous. The markings are quite heavy. The fore wings on the under side are very pale fulvous, yellowish at the tip, mottled with ferruginous. The hind wings are ferruginous on the under side, mottled with yellow. The spots are quite large, consisting of lines and dashes, and a marginal row of small lunulate spots, pale yellow or white, slightly silvered. Expanse, 1.50 inch.
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.
Early Stages.—Unknown.
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.
This pretty little butterfly occurs in Labrador, across the continent as far west as northern Alaska, and is also occasionally taken upon the alpine summits of the Rocky Mountains as far south as Colorado.