Genus Thanaos 



the under side as a series of 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, i. 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. 



Bri:{0 occurs from the Atlantic to the Pacific, ranging from the 

 latitude of New England to that of Arizona. 



(2) Thanaos icelus, Lintner, Plate XLVIII, Fig. 17, 5 ; 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, i. 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 and Arizona. 



(3) Thanaos somnus, Lintner, Plate XLVIII, Fig. 2, 6 (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, 6, 1.25 inch; ?, 1.50 inch. 



Early Stages. — But little is known of these. 



All of the specimens I 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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