UNIVERSITY OF CALIFORNIA PUBLICATIONS • 



IN 



ZOOLOGY 



Vol. 21, No. 7, pp. 245-274, 25 figures in text April 18, 1922 



A STUDY OF THE CALIFORNIAN FORMS OF 



THE MICROTUS MONTANUS GROUP 



OF MEADOW MICE 



BY 



REMIN( " I KELLOGG 

 (Contribution from the Museum of Verteorate Zoology of the University of California) 



INTRODUCTION 



The present paper is a further report upon the writer's studies 

 on the meadow mice of the genus Microtus in California. The first 

 report consisted of "A revision of the Microtus oaUfornicus group of 

 meadow mice" (Kellogg, 1918). The material upon which the paper 

 now offered is based consists of three hundred and sixty-seven speci- 

 mens, representing sixty-three localities within the state of California, 

 and further series of specimens bearing upon the problem from outside 

 this state. 



Microtus m-ontanus, under the name Arvicola niontana, was first 

 made known to science by Titian R. Peale, its discovery being one of 

 the results of his explorations through northern California. The 

 specific name he applied to the mouse was doubtless in allusion to the 

 nature of the type locality, which was near the headwaters of the 

 Sacramento River close to Mount Shasta. Within the state of Cali- 

 fornia the species ranges zonally from Transition to Hudsonian, each 

 inclusively. It is apparently restricted to alpine meadows in the 

 Sierra Nevada and the Trinity Mountains, and to the lowland marshes 

 of the Modoc region, in the northeastern part of the state. Since the 

 discovery of Microtus montanus, several closely related forms have 

 been found, the group thus constituted ranging far beyond the con- 

 fines of California. One race has recently been described from so far 

 distant as Wyoming. Altogether, six forms of this group are recog- 

 nized, of which three, the ones occurring in California, are treated 

 in considerable detail in the present paper. 



