ALLEN: AMERICAN COLLARED LEMMINGS. 517 



in patches or irregular areas is apparently characteristic of old and 

 less vigorous individuals, whereas in the younger though mature 

 animals, the change takes place much more regularly. In these a 

 sharply outlined area of newly grown hairs spreads from the median 

 area of the back, laterally, or more exactly, the white winter pelage 

 gradually drops out as the new hair comes in, disappearing first from 

 the nape and shoulders and last along the sides. A nearly full-grown, 

 but not old, specimen taken May 10th at Nastapoka River shows a 

 narrow gray band along eacli side, in which the new fur is still mixed 

 with the remnants of the while pelage of winter, yet the latter seems 

 to have been shed at about the same rate that the new has come in, 

 and the new hair by its rapid growth has nearly equalled the old 

 in length. The result is a pale gray, due to the even mixture of the 

 two, sharply defined from the dorsal area of wholly new fur, and quite 

 without the ragged effect seen in old animals in which the slower 

 maturity of the new coat causes the remnants of the older and longer 

 hair to stand out in patches. No series illustrative of the fall molt 

 is available. A young one, taken May 1st, at Richmond Gulf, 

 Hudson Bay, is but 86 mm. long, and must have been born in March 

 or April. It is in the summer pelage, which is doubtless the older 

 phylogenetically. 



Geographic distribution. — This species is confined so far as known 

 to the barren-ground area of the Labrador Peninsula, from (probably) 

 the Straits of Belle Isle on the southeast to about the latitude of 

 Great Whale River (')5° N.) on the west side. It is also found on 

 some of the small islands along th? eastern side of Hudson Bay, 

 but on the west side of the bay its place is taken by D. r. richardsoni. 

 Between the ranges of these two species, James Bay intervenes, 

 the borders of which are unsuited for lemmings on account of their 

 wooded character. In the interior of the Labrador Peninsula the 

 details of distribution are yet to be worked out. Low, however, 

 reports it from Lake Michikamau. On the eastern coast it is not 

 uncommon from Hamilton Inlet northward, and probably continues 

 farther south following the barren Arctic strip along the coast to the 

 Straits of Belle Isle (52° N.) Near Battle Harbor in 1906, I found 

 in several places on the neighboring Great Caribou Island, the rather 

 characteristic deposits of dung made during A\'inter in certain parts 

 of their tunnels under the snow. It is unlikely that lemmings cross 

 Hudson Strait with its baffling counter-currents. Those that at- 

 tempted it would probably be carried to the Atlantic, or back on 

 the northern side of the Strait toward Hudson Bay. Along the 



