206 U diversify of (California FiiblicationH in Zoology. [Vol. 7 



eal work in Iliiniboldt County in the interests of the University 

 of California, also secured a number of mammals. 



Localities represented in the entire collection of mammals 

 are: Quinn River or Mason's Crossing, various points in the 

 Pine Forest Mountains, and Virgin Valley. Nearly all of the 

 localities referred to in this report may be found upon the Disas- 

 ter Sheet of the United States Geological Survey's Topographic 

 ]\Iap of the United States. 



The writer is indebted to the Biological Survey, United States 

 Department of Agriculture, for the loan of material necessary 

 for comparison ; to Dr. C. Hart Merriam, Mr. H. W. Henshaw, 

 ]Mr. Vernon Bailey, and Mr. E. A. Preble for the identification of 

 various specimens ; to Mr. Wilfred H. Osgood, Assistant Curator 

 of ]\Iammalogy and Ornithology, Field Museum of Natural Plis- 

 tory, Chicago, for the identification of specimens of Peromyscus 

 submitted to him; to Professor Charles A. Kofoid, head of the 

 Department of Zoology of the University of California, and to 

 ]\rr. Joseph Grinnell, Director of the California Museum of Verte- 

 brate Zoology, both of w^hom have directly assisted the writer by 

 generous criticism and direction. 



Methods of IMeasurement. 



All measurements are in millimeters unless otherwise specified. 



Cranial jMeasurements, except where otherwise specified, 

 are taken as follows : 



Greatest length: length over all, from extreme anterior tip 

 of nasals to most posterior point on skull. 



Basilar length of Hensel: from inferior lip of foramen mag- 

 num to posterior margin of alveolus of incisor. 



ZygornaHc width : distances between outermost surfaces of 

 zygomatic arches. 



Mastoid icidtli : greatest width of skull at mastoid processes. 



Interorbital eonstriction: width of the most constricted part 

 of the interorbital portion of cranium, including slight lateral 

 bulges just below dorsal surface of skull, when Ihcse are ])res(Mit. 



I id er parietal : length, measured antero-posteriorly on skull 

 along median line; width, measured laterally in wadest place. 



