1895.] MYODES LEMMUS. 61 


1883. The mountains on the Norwegian-Swedish frontier, from 
the northernmost portions of Nordland (Saltdalen), up to 
the distriets about Tromsö. 
It is probable that both the migrations of 1883 have been 
allied to each other, but special reports from the interven- 
ing country (the southern portions of Nordland) are wanting. 
1887. The Langfjeld and Dovre mountains; northwards by Sönd- 
mör and Romsdal, to the north side of the Trondhjems Fjord. 
1890. Söndre Trondhjem's Amt, Gudbrandsdal and Österdal; not 
considerable, however, but formed the advance guard of the 
abnormal production in the following year. 
1891. The mountains of Dovre, Østerdal, and Gudbrandsdal; not 
so extensive in Jotunheim and the Filefjeld. The migration 
extended to Kongsvinger, the regions above the Chrishamia 
Fjord, in Modum, and Thelemarken. 
1894—? Söndmör and Nordfjord; the Filefjeld, including Sogn; 
Voss down to Hardanger and Hallingdal. 
At the close of 1894, the migration had extended to Thele- 
marken and the south end of the lake Kröderen. 
20.  Varieties. 
Several authors have stated that, this species is "extremely 
variable in its size and markings.” To this I would reply, first, 
that the size of full grown animals is hardly more variable 
than in other small rodents, while it must be remembered that 
the migrating indjviduals consist, almost entirely, of young spe- 
eimens of various litters, of which not all are fully matured. 
In respect to the colour, it must sooner arouse astonishment 
than otherwise, that its variegated coat should be so wonderfully 
uniform that scarcely any striking dissimilarity can be found 
amongst thousands. There may, certainly, be some slight differ- 
ence in the width of the black patch over the shoulders; and the 
summer dress differs also, to some extent, from the winter one 
