Genus Thanaos 
the under side as a series ot pale-yellowish spots more or less 
distinct. The hind wings have a double series of faint yellow 
spots; these as well as the marginal spots of the primaries are 
very distinct on the under side. Expanse, 1.25-1.60 inch. 
Early Stages. —The caterpillar feeds on oaks, Galactia, and 
possibly Baptisia. The life-history has been only partially ascer¬ 
tained, in spite of the fact that the insect has a wide range and is 
not uncommon. 
Briqo occurs from the Atlantic to the Pacific, ranging from the 
latitude of New England to that of Arizona. 
(2) Thanaos icelus, Lintner, Plate XLV 1 II, Fig. 17, $ ; Plate 
VI, Fig. 27, chrysalis (The Dreamy Dusky-wing). 
Butterfly. —Prevalently smaller in size than the preceding spe¬ 
cies. The under side of the wings is paler than the upper side, 
and the outer third of both the primaries and secondaries is 
marked with a profusion of small indistinct yellow spots, which 
do not form well-defined bands as in the preceding species. On 
the upper side of the fore wing the median area is generally 
marked by a broad band of pale gray, but this is not invariably 
the case. Expanse, 1.00-1.20 inch. 
Early Stages. —These have been described by Scudder. The 
caterpillar feeds on a variety of plants, as the aspen, oaks, and 
witch-hazel. 
Icelus ranges across the continent from Nova Scotia to Oregon, 
and south to Florida ana Arizona. 
(3) Thanaos somnus, Lintner, Plate XLVIII, Fig. 2, £ (The 
Dark Dusky-wing). 
Butterfly. —A little larger than the preceding species, espe¬ 
cially in the female sex. The male is generally quite dark, the 
banding of the fore wing on the upper side obscured. The hind 
wings have a row of light marginal and submarginal spots, more 
distinct on the under side than on the upper. The female gen¬ 
erally is light gray on the upper side of the wings, with broad 
median and submarginal bands of dark brown, tending to fuse or 
coalesce at a point near the origin of the first median nervule. 
Expanse, $, 1.25 inch; $, 1.50 inch. 
Early Stages. —But little is known of these. 
All of the specimens 1 have ever seen came from southern Florida. 
(4) Thanaos lucilius, Lintner, Plate XLVIII, Fig. 10, 6 ,* 
Plate VI, Figs. 30-32, chrysalis (Lucilius’ Dusky-wing). 
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