Genus Colias 



side is bright lemon-yellow, with broad black margins on both 

 wings. The female is paler, with the black margin of the hind 

 wing lacking or very faintly indicated, and the margin of the 

 fore wing much broken up by yellow spots. On the under side 

 the wings of the male are dusky-orange, pale yellow on the disk 

 of the primaries; the wings of the female on this side are pale 

 yellow. Expanse, $ , 2. 00-2.10 inches; ?, 2.25-2.30 inches. 



Early Stages. — Undescribed. 



The home of this species is on the Coast Range of northern 

 California. 



(6) Colias alexandra, Edwards, Plate XXXV, Fig. 6, $ ; Fig. 

 7, $ (The Alexandra Sulphur). 



Butterfly. — Larger than C. philodice. The male is pale canary- 

 yellow, with much narrower black borders than the preceding 

 species. The female is pale yellow or white, without black bor- 

 ders, or, at most, faint traces of them at the apex of the pri- 

 maries. On the under side the wings are silvery-gray, yellow 

 only at the base and on the inner margin of the primaries. The 

 discal spot on the hind wings is white. Expanse, S , 1.85 inch; 

 ?, 2.10-2.30 inches. 



Early Stages. — The caterpillar is uniformly yellowish-green, 

 with a white band on each side, broken with orange-red dashes 

 running through it. The chrysalis, which resembles that of C. 

 philodice in form, is yellowish-green, darkest on the dorsal side, 

 and adorned with three small red dots on the ventral side of the 

 abdomen near the wing-cases. The caterpillar eats Astragalus, 

 Thermopsis, and white clover. Expanse, $ , 1.90-2. 15 inches; 

 ? , 2.00-2.30 inches. 



The species is found in Colorado and the mountain regions 

 to the north and west of that State. 



(7) Colias interior, Scudder, Plate XXXV, Fig. 10, $ ; Fig. 1 1, 

 ? (The Pink-edged Sulphur). 



Butterfly. — The male on the upper side closely resembles C. 

 philodice, but is smaller, the fringes of the wings rose-colored. 

 The female is pale yellow above, more frequently white, with the 

 tips of the fore wings lightly marked with blackish. On the 

 under side the fore wings at the apex and the entire surface of 

 the hind wings are rusty orange-yellow. The discal spot on the 

 hind wings is silvery, bordered with rosy-red. Expanse, $ , 1.30- 

 1.75 inch; $, 1.60-2.00 inches. 



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