Butterfly.—The male on the upper side is pale yellow, with a greenish tinge on the hind wings; the black borders are narrow; the fringes are pink. The female on the upper side is white, with very little or no black on the outer borders, the black marking being confined to the apex of the fore wings. On the under side the wings are much as in C. interior, and it is possible that the two forms are varieties of one and the same species. Expanse, 1.60-1.85 inch.
Early Stages.—Little is known of these.
Pelidne is rather abundant in Labrador at the proper season, and ranges thence westward and northward in boreal America.
(10) Colias nastes, Boisduval, Plate XXXVI, Fig. 11, ♂; Fig. 12, ♁ (The Arctic Sulphur).
Butterfly.—Easily recognized in both sexes by the pale-greenish tint of the wings and the tendency of the outer border of the fore wings of the male to become divided, like those of the female, by a band of pale spots. Expanse, 1.50-1.65 inch.
Early Stages.—Unknown.
This is an arctic species, which is found in Labrador, Greenland, the far North in British America and Alaska, and on the summits of the Rocky Mountains in British Columbia.
(11) Colias behri, Edwards, Plate XXXVI, Fig. 17, ♂ (Behr's Sulphur).
Butterfly.—This very rare little species may be easily recognized by the dark-greenish tint of the upper side of the wings and the light spot on the upper side of the hind wings. The female has the outer borders dusky like the male, the dusky shade running inward on the lines of the veins and nervules. Expanse, 1.50 inch.
Early Stages.—We know little of these.