106 



trionale, states it to be found in Greenland, Iceland and Labrador, 

 and I presume his figure to have been taken from, and his species 

 referable to, the species found in the former localities. The male 

 of C. Pelidne, as figured by Boisduval in his Icones historique des 

 Lepidopteres, is much like the male of C. interior ; while the figures 

 given by Herrich SchajfFer (which I cannot think, with Menetries, 

 were copied from Godart) closely resemble C. labradorensis^ if they 

 are not of the same species, though the species described as Pelidne 

 by Menetries, on page 84 of his St. Petersburg Catalogue, does not 

 seem to be the same as C. lahradorensis. " Lederer," says 

 Menetries, " pretends that he knows Pelidne only from Labrador." 

 I think it must be that the true C. Pelidne is not found in Labra- 

 dor, and that my C. lahradorensis, which cannot be referred to 

 it, is the species seen by Lederer, and hitherto undescribed. 

 Other species, known in boreal Europe, have also been stated to 

 have been found in boreal America, but I suspect that, in all 

 these cases, a close resemblance has been mistaken for an identity. 

 Of the two Arctic species, I know nothing, but none of the species 

 I here describe are the C. Boothii or the C. Chione of Curtis, 

 described in the Appendix to Ross's Second Voyage. 



There seem to be three distinct faunje in boreal America, in each 

 of which the genus Colias is represented by a distinct species ; so far 

 as is simply indicated by an examination of the species of diurnal 

 Lepidoptera which I have seen from there, the easternmost is con- 

 fined to a narrow limit, comprising only the eastern portion of Labra- 

 dor ; the central appears to include in general all the country watered 

 by streams flowing into Hudson's Bay, whether upon its eastern, west- 

 ern or southern coast ; and the westernmost includes the Rocky Moun- 

 tain region, and the country west of it. These faun 33 are very closely 

 related to one another, being connected most intimately by true repre- 

 sentative species ; they are connected together more intimately than 

 any of them are to the faun« lying immediately south, — in the north 

 temperate region the relationship between these two sets of faunaj 

 being shown rather by what may be termed equivalent species, as, for 

 instance, C. Philodice, in comparison with C. lahradorensis or C. in- 

 terior ; for there may be said to be three sorts of species, which may 

 be designated thus : — 



1°. Representative species, or those forms occupying different geo- 

 graphical areas, which exhibit an intimate homology in their specific 

 peculiarities, such as the three species of Colias here described in 

 comparison with one another. 



2°. Equivalent species, or those forms occupying diflFerent geo- 

 graphical areas, which do not exhibit such an intimate homology in 

 their specific peculiarities, but simply represent the genus in the faunae 



