105 



answer exactly to the description given by Boisduval of C. 

 Eurytheme and C. Amphidusa, and I consider them to be the 

 same species, for which the name of Eurytheme must be retained ; 

 the only difference between the two which acquires any degree 

 of constancy is the depth and breadth of the orange tint upon 

 the upper surface, which, in the specimens that correspond to 

 his Amphidusa, covers the whole wing not occupied by the black 

 border; while, in those corresponding to his Eurytheme, it covers 

 only a central portion, and is not so deep, being mixed more with 

 yellow ; but this depth and extent of the tint appears also to be a 

 variable character, and not to separate into two well-marked 

 groups these Western individuals. I have seen specimens from 

 Minnesota, Lake Superior and Texas, which seem to correspond 

 entirely to those of the Pacific Coast. Mr. Edwards first brought 

 to my attention the fact that the upper surface of this species has 

 a purplish lustre when seen by oblique light, especially in those 

 from California and Texas. This is undoubtedly the species 

 referred to by various authors in stating that C. Edusa and 

 C. Chrysothevie were found in California, and I suspect its pre- 

 valence even to the Atlantic border, south of New York, because 

 it has also been asserted by authors that the two species just 

 mentioned had been found there. I have not seen any specimens 

 from the Middle States which could have been mistaken for them, 

 and so cannot speak with any certainty. 



Boisduval mentions, in his description of C. Amphidusa, that 

 the only female he had seen was pale. There are no albinic 

 specimens among the females I have seen; but if they occur, it 

 only agrees, in this respect, with other allied species. Morris, in 

 his Synopsis, gives Boisduval's authority for the localization of 

 C. Hyale in California. I do not know where Boisduval asserts 

 this, unless it be in the 3d Series of the Annales de la Societe 

 Entomologique de ]France, which I have not seen, but if he does, it 

 may have been a mistaken reference of this albinic female of C. 

 Eurytheme to that species. 



There are three species of Colias in boreal America, — C. labra- 

 dorensis, C. interior and C. occidentalis, — described below. The 

 first inhabits Labrador, the second the interior of the continent, 

 and the third the western portion, including the Rocky Mountain 

 region. They are all closely allied to one another and to C. 

 Pelidne, Boisd. and Lee. They do not, any one of them, agree 

 with the figures and descriptions given of C. Pelidne, — under 

 which name, I suspect, more than one species is confounded. 

 Boisduval, in his first description of C. Pelidne, in Boisduval and 

 Leconte's Histoire generale des Lepidopteres de I'Amerique Septen- 



