THE ALPINE FAUNA. 325 



original home in this case does not agree with that 

 centre. 



Melitcea, a genus to which some of our British 

 Fritillaries belong, has also some typically Alpine 

 members. Two of these, viz. M. cynthia and M. 

 asteria, are peculiar to the Alps, the latter being 

 only found at considerable elevations. Most of the 

 remaining fourteen European species are also found 

 in Central Asia. Thus the isolated M. mattirna, 

 which in Europe is confined to Lapland, is also 

 known from the Altai' Mountains, which again are 

 near the centre of distribution, since some species 

 of Melitcea range across the Northern Pacific to 

 Western North America. 



The small British Mountain Ringlet, and also the 

 Scotch Argus, belong to a genus of butterflies which 

 is very characteristic of the European Alps. But 

 owing to its enormous geographical distribution, its 

 probable home is somewhat difficult to ascertain. 

 Nevertheless it is a noteworthy genus, especially so 

 from the fact that the two British species Erebia 

 epiphron and E. czthiops are taken at first sight 

 for true Arctic migrants. As neither of them, how- 

 ever, occurs in Scandinavia, Greenland, or Arctic 

 America, this supposition must be abandoned. They 

 must be looked upon as species which once had a 

 wider range in the southern parts of the British 

 Islands, and which have survived in a few isolated 

 localities, where they are apparently on the verge of 

 extinction. 



