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The West American Scientist. 



a good species, until Mr. W. H. Edwards proved otherwise by 

 breeding eurytheme from eg-gs laid by C. eriphyle. The earliest 

 spring form in Texas and California is ariadne, a smallish butter- 

 fly, about an inch and a half across the wings, pale sulphury with 

 orange patches on the fore wings, and the dark marginal borders 

 are ill-developed. A little later in the same localities, or as the 

 only winter form further north, comes Keewaydin, much like 

 Ariadne, but slightly larger, duller in general color, with the 

 orange patches more suffused over the wings, the under side also 

 is decidedly more ochreous, that of Ariadne having a tendency to 

 greenish, with rosy fringes Then the summer form Eurytheme 

 type is much larger, over two inches in expanse, and vivid orange, 

 the sulphur yellow only appearing on the costa, the inner margin 

 of the secondaries, and the yellow spots in the marginal band of 

 the female. The under side is more like Keewaydin than Ariadne. 

 In this locality (Swift Creek, Custer Co., Colo.) another very 

 different form, which I will call intermedia, is found flying in the 

 summer. It is larger than Keewaydin, the expanse of wings in 

 the female being over two inches (about fifty -five millimeters), the 

 color of the wings is pale sulphur, with distinct orange patches on 

 the primaries, much as in Ariadne, but the wings are much suf- 

 fused with black scales near their bases; the marginal borders are 

 fairly well-developed. The under side is pale greenish yellow, 

 not ochreous, as in eurytheme type and Keewaydin, nor have the 

 secondaries the greyish appearance of Ariadne. The fringes are 

 only slightly rosy. So much for the orange forms of eurytheme; 

 there is yet another, of a delicate sulphur tinge, almost like C. 

 philodice, and this is called eriphyle, Colias hagenii being also a 

 synonym. This form eriphyle flies with the orange varieties, and 

 is itself seasonally dimorphic, as pointed out by Mr. W. H. 

 Edwards ('Canad. Ent. 1887, p. 173). On November 9, 1887, I 

 caught a female specimen of the autumn brood of eriphyle in this 

 locality. This may be called autumnalis, and has much the same 

 relation to typical eriphyle as Ariadne has to typical eurytheme 

 (vide W. H. Edwards, loc. cit.), being smaller, with narrower 

 borders, and the hind wings more greyish-green. Whitish females 

 occur of eurytheme, Keewaydin and intermedia, resembling 

 analogous forms in other species of the genus, these may be call- 

 ed pallida. The forms, then, of C, Eurytheme may be classified 

 as follows: 



Colias eurytheme Bdv. a. orange forms. 



I. Spring or winter forms. 



1. Ariadne Edw. 



2. Keewaydin Edw. 

 o. 2 pallida. 



II. Summer forms. 



3. Typica^=Eurytheme Bdv. 

 a $ pallida. 



