Drummond Vole 517 



shovels for winter use; the winter coat is white. 



These animals are found only in the Arctic 



regions. 

 Evotomys Coues, 1874. Like Microtus, but with red 



back and well-developed ears. 

 Fiber F. Cuvier, 1800. The Muskrats are known at 



once by their great size, brown fur and fiaty 



blade-like, scaly tail. Otherwise a Muskrat is 



merely a magnified Microtus. 



About 70 North American species and races of the genus 

 Microtus appear in the latest lists. Their minute differences, 

 individual variations, and endless intergradations are a 

 puzzle to most naturalists. It is impossible to identify them 

 without elaborate study of many specimens — skull and skins. 

 One can only hope and believe that this present repellent 

 multiplication of names will give place to a simplified compre- 

 hensible system that shall be a help to the study of the animal 

 itself. 



I feel something like desperation when endeavouring to 

 identify any of the genus by a book or even by labelled speci- 

 mens. Especially when I seek as heretofore to be guided by 

 external characters. They prove most unreliable. Fortun- 

 ately there is another means, the safest of all, the characters 

 presented by the teeth; and in this department the Meadow- 

 mice are most happily placed. They may be coarse-furred, 

 coarse feeders, with coarse, blunt muzzles, but they are pos- 

 sessed of the most exquisite little carved ivories in the way 

 of molars that any of our creatures can boast. The teeth of 

 the Deermice look very coarse and bumpy beside these; their 

 white enamelled lines and curves in high relief are inlaid 

 with brown dentine intaglio constituting at once a thing of 

 beauty to please the naturalist's eye, a graven record of the 

 animal's development, and the safest of all labels. 



Vernon Bailey has made a special study of the group.' I 

 reproduce his diagnoses. 



' Revision, Microtus, N. A. Fauna, No. 17, 1900. 



