Genus Colias 



not form as high a keel-shaped projection from the ventral side 

 as in that genus. 



This genus is very extensive, being represented throughout 

 the temperate regions of both hemispheres, and also occurring in 

 the cooler portions of South America, especially along the ranges 

 of the Andes. One species is found in temperate South Africa. 

 The brightly colored butterflies, which are sometimes found con- 

 gregating in immense numbers in moist places, are familiar ob- 

 jects, and swarm upon the clover-fields and by the roadside in the 

 summer months throughout the United States. 



(i) Colias meadi, Edwards, Plate XXXVI, Fig. 5, 6 ; Fig. 

 6, $ (Mead's Sulphur). 



Butterfly. — The wings on the upper side are orange, greenish 

 on the under side. The discal spot on the lower side is centered 

 with green. Expanse, 1.75 inch. 



Early Stages. — The life-history has been written by Edwards, 

 and may be found in the pages of the " Canadian Entomologist," 

 vol. xxi, p. 41. The larva feeds on clover. 



The species is alpine in its habits, and is found in Colorado 

 from nine to twelve thousand feet above sea-level. 



(2) Colias elis, Strecker, Plate XXXVI, Fig. 13, $ ; Fig. 14, 

 $ (Strecker's Sulphur). 



Butterfly. — This species is discriminated from the preceding 

 principally by the narrower black margins on the wings of the 

 male and the more abundant yellow maculation of the borders in 

 the female. Expanse, 1. 55-1.90 inch. 



Early Stages. — Closely resembling those of the preceding spe- 

 cies, of which it may be only a varietal form. 



The habitat of the species is on the lofty peaks of the Western 

 Cordilleras. 



(3) Colias eurytheme, Boisduval, Plate XLVIII, Fig. 18, $ ; 

 Plate XXX111, Fig. 5, $, under side; Plate II, Fig. 1, larva; Plate 

 V, Fig. 53, chrysalis (Eurytheme). 



Butterfly. — This species has been made in recent years the 

 subject of exhaustive study, and has been discovered to be 

 strongly polymorphic — that is to say, liable to great variation. 

 Not only does albinism assert itself in the production of white 

 forms, but there are many seasonal and climatic forms. We are 

 not yet through with our studies, and there is doubtless much 

 more to be ascertained. The figures cited above represent the 



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