UNIVERSITY OF CALIFORNIA PUBLICATIONS 



ZOOLOGY 



Vol. 12, No. 7, pp. 301-304 April 15, 1914 



A SECOND SPECIES OF THE MAMMALIAN 



GENUS MICRODIPODOPS FROM 



CALIFORNIA 



BY 



JOSEPH GBINNELL 

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



The remarkable rodent genus Microdipodops came to the attention 

 of naturalists only about twenty-three years ago. So far as at present 

 known, it occupies a more restricted area than any other genus of 

 Sonoran mammal, namely, the central and northern parts of Nevada, 

 and the adjacent extreme southeastern portion of Oregon and eastern 

 edge of California. This genus may thus be inferred to be an essen- 

 tially Great Basin product. Even within this limited region geo- 

 graphic speciation is strongly in evidence, so that four species have 

 already been distinguished by name. The existence of any represent- 

 ative of the genus within the state of California was first discovered 

 by Dr. Walter K. Fisher, who, in August, 1900, sent to the United 

 States Biological Survey some specimens obtained by him in Sierra 

 Valley, Plumas County, near the town of Vinton. One of these speci- 

 mens became the type of Microdipodops calif o miens C. II. Merriam 

 (1901, p. 128). This has continued until the present time the only 

 record of the occurrence of the genus in California. 



In July, 1912, two collectors from the California Museum of Verte- 

 brate Zoology, Messrs. Chas. D. Holliger and Norman Stern, trapped 

 for mammals in the vicinity of Benton, Mono County, California. As 

 one result of their work there, Microdipodops was found to be rather 

 commonly represented, and a series of ten specimens (nos. 17031- 

 17040) was secured. These prove to represent a species altogether 

 distinct from M. californicus, and also different from the other three 

 species of the genus characterized to date. 



