Feb., 191 2. Mammals of Illinois and Wisconsin — Cory. 235 



Goss's Lemming Mouse {Synaptomys cooperi gossii) . 



''This mouse is found on hillsides in high, dry, blue grass pastures, 

 where flat stones are irregularly scattered over the surface; it especial- 

 ly prefers what are known as 'wood pastures' containing little or no 

 undergrowth. . . . Cooper's field mouse has been found breed- 

 ing from February to December. It has never been known by the 

 authors to bring forth more than four young at a time. . . . The 

 nest of this species is always under cover, generally in a hollow log or 

 stump, and is composed of fine grass. It is not so securely built as the 

 nests of some of the other species of this family. 



"Cooper's mice live in winter chiefly upon the stems of blue grass 

 and the more tender portions of the white clover. Stores of these foods 

 may be found near their winter quarters. In November, 1883, a large 

 quantity of the tuberous roots of the plant commonly called 'wild 

 artichoke' {Helianthus doronicoides Lam.) were found in one of the 

 store-houses of a colony of these mice. . . . Cooper's mouse is 

 the most active representative of its family in this locality. It is most 

 frequently found by turning over stones and logs, beneath which it 

 remains concealed, especially in winter. Upon removing their cover- 

 ing, as the light reaches them, they are off like a flash for their sub- 

 terranean paths, leaving the collector to mourn for a valuable speci- 

 men, a glimpse of which he caught as it fled before his hand could 

 grasp the prize." (Amer. Nat., XIX, 1885, pp. 114, 115.) 



