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, $, 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. io, $ ; Fig. 11, 
? (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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