1913] Grinnell: Calif ornian Species of Sorex 181 



It would appear, however, that the present study is war- 

 ranted, even though far from an ideal quantity of material is as 

 yet available. Since difficulty has been experienced by the author 

 in learning how to determine the species of shrews described in 

 previous literature, he has tried to provide here a ready means 

 for identifying at least those six species thus far known to occur 

 in the restricted region roughly indicated in the term west- 

 central California. 



I have given up trying to use tooth characters among the 

 species here dealt with, because of the smallness of the available 

 series of each, and because of the extraordinary amount of wear to 

 which shrews' teeth are subject, with resulting profound modifi- 

 cation in relative size and pattern. Inexperience in studies upon 

 teeth is another good reason for my refraining from expressing 

 opinions based upon dentition. 



The opportunity is taken in this paper to describe and name 

 a race of the Monterey shrew, from the western flank of the 

 Sierra Nevada, and also to offer a few comments upon the general 

 faunistic peculiarities of the marshlands of west-central 

 California.' 



KEY TO THE SHREWS OF WEST-CENTRAL CALIFORNIA 

 By Size 



Extremely small (total length about 90 mm., hind foot about 11 mm.) 



Sorer calif ornicus 



Fairly small (total length about 102 to 105 mm., hind foot about 



12 mm.) 



Color warm brown S. vagrans 



Color sooty brown or black 



Braincase high »S'. halicot tes 



Braincase flattened S. sinuosus 



Medium-sized (total length about 116 mm., hind foot about 15 mm.) 



, S. in i nit, n iii nsis 



Large (total length about 146 mm., hind foot about 17 mm.) .S'. pacificus 



By Color 

 Grayish brown, with pepper-and-salt effect; silvery beneath; size 



extremely small Sorex calif ornicus 



Warm brown; brownish gray beneath 



Bright rusty brown; size very large (length about 146 mm.) 



S. pacificus 



Vandyke brown; size small (length about 103 mm.) S. vagrans 



