MAMMALS. 59 



tiired, but they soon became quiet and gentle. They would some- 

 times try to nip my fingers, but when proper care was taken they 

 would let me take them in my hands, and would make little effort 

 to escape. 



They are prolific breeders, and the four to eight 3"oung in a litter 

 are brought forth in the warm soft nests in dry and secluded cavities 

 underground, among rocks, hollow trees or logs, in boxes or crevices, 

 or in corners of buildings. They quickly mature and are soon run- 

 ning about in the blue-gray coats which are worn through most of the 

 first year. Several litters are raised each season, and the increase 

 is so rapid that any safe retreat like a vacant building is soon, over- 

 run by them. Outdoors the little owls, weasels, coyotes, and foxes 

 pick them up so rapidly that their abundance is well checked, and 

 when the breeding season is over their numbers steadily decrease 

 until the next spring. 



They do not hibernate or become noticeably fat, but during the 

 autumn they store up considerable quantities of seeds, grain, and 

 nutlets for winter use. Buried under the deep snows of winter 

 they live safely and in comparative comfort and luxury next to the 

 ground in the tunnels which they make under the snow. They 

 also come to the surface and run over the soft snow, and lines of 

 delicate tracks may be traced in winter from one log to another, from 

 tree to tree, or from rock pile to cliff, and thus some clue to their 

 winter habits is obtained. They climb trees readily and often oc- 

 cupy hollow trunks or even old woodpecker holes in stumps and trees. 



Mountain Lemming Mouse: Phenncomys orophihis Merriam. — 

 These rare little lemming mice somewhat resemble the meadow mice, 

 but differ radically from them in having molar teeth with well- 

 developed, roots and different type of enamel pattern. In external 

 characters they may be distinguished by their small size, light gi'ay 

 color, and by the tail, which is slender and does not noticeably taper. 

 x\n adult male collected on the Swiftcurrent Eiver below jNIcDermott 

 Lake measured, in millimeters: Total length, 122; tail, 30; hind foot, 

 18. Their measurements serve to distinguish them from almost any 

 of the other little rodents except the red-backed mouse, from which 

 they differ strikingly in color. 



In the spring of 1895 Howell and I collected a dozen specimens 

 of these little mice at St. Mary Lake, one at Midvale, and one at 

 Summit; in August, 1917, I caught one in the open valley just 

 below McDermott Lake ; and in April, 1918, I found one dead in the 

 trail near Kintla Lake. These records would indicate that lemming- 

 mice are unusually common in the Glacier Park region, and may 

 be found anywhere along the lower slopes of the park or in' the 

 open Hudsonian Zone area near timberline. Most of the specimens 



