﻿90 



NORTH AMERICAN FAUNA. 



[No. 10. 



Color. — Upper parts sepia brown; under parts ashy gray, washed 

 with buffy on throat and breast, and' sometimes on belly also; tail 

 bicolor: dark brown above, whitish beneath. 



Cranial and dental characters. — Skull smallest of the known Ameri- 

 can Shrews except 8. Minus {15.5 by 0.5 mm.^), and differing from all in 

 the subgeneric characters already described. The brain case is low, long, 

 and rather narrow, the constriction relatively broad, and the rostrum 

 medium. Viewed from below, the sides of the rostrum converge grad- 

 ually , without apparent angle between the molariform and unicuspidate 

 series. The lower jaw is relatively large and heavy, and the styliform 

 angular process Is very long. The molars do not x)resent any marked 

 peculiarities. The n^nicuspids, viewed from the outer side, seem to be 

 three in number, the third and fifth being so minute and internal as to 

 escape notice; in fact, in some skulls they cfin not be seen at all from 

 ohe outer side. The middle incisors have a large inner lobe. 



General remarTcs. — Sorex hoyi has been supposed to have a very 

 restricted distribution, but the specimens secured in recent years show 

 it to range from British Columbia on the west almost to Labrador on 

 the east. It is the type, and, so far as known, the sole representative, 

 of Baird^s subgenus Microsorex, a division which in the future is likely 

 to be raised to full generic rank. 



The material now available is insufficient to determine whether or 

 not the British Columbia form is entitled to subspecinc separation. 



Measurements, — Average of 3 alcoholic specimens (in good condition) 

 from Elk Eiver, Minn. : Total length, 81.7 mm. ; tail vertebrae, 30.7 mm, ; 

 hind foot, 10.7 mm. Average of 5 alcoholic specimens from Godbout, 

 Quebec, Canada: Total length, 83 mm.; tail vertebrae, 32 mm.; hind 

 foot, 10.5 mm. A single alcoholic specimen from Fort St. .Tames, Stuart 

 Lake, British Columbia, measures : Total length, 88 mm. ; tail vertebrae, 

 31 mm.; hind foot, 9.5 mm. 



Specimens examined. — Total number, 23, from the following localities: 



Canada: Godbout, Quebec, 5; Digby, Nova Scotia, 1; Red River Settlement, 

 Manitoba, 1; Fort St. James (Stuart Lake), British Columbia, 1. 

 Minnesota : Elk River, 11. 

 North Dakota : Devils Lake, 1. 

 New York : Locust Grove, Lewis County, 3. 



Subgenus NEOSOREX Baird, 1857. 



Neosorex Baird, Mammals N. Am. p. 11. PL XXVI, 1857. Type, Neosorex navigalor 

 Baird. 



Geographic distribution. — The Sierra Nevada of California, the Rocky 

 Mountains from Colorado northward, and boreal parts of eastern ^N'orth 

 America from plains of l^orth Saskatchewan to Minnesota, the Adiron- 



1 A very old skull from Locust Grove, N. Y., measures only 14 by 5.8 mm., and is 

 the sm;illest Shrew skull I have ever seen. A young adult from the same locality 

 measures 15 by 6.5. mm. 



