﻿"Dec, 1895 



SOREX PALUSTRIS. 



91 



(lacks of New York, nortliern New Eiigiand, and eastern Canada on 

 both sides of the St. Lawrence. 



Diagnosis.— FQQt hirge; hind foot very long, broad, somewhat oblique, 

 and fimbriate for swimming; toes all fimbriate, the third and fourth 

 united at base and slightly webbed. 



The known members of the subgenus are of large size (much larger 

 than any species of true Sorex)^ have long tails, and are white under- 

 neath at least part of the year. I am not aware of any cranial or 

 dental characters by which Neosorex may be distinguished from Sorex^ 

 although the brain case is unusually broad and broadens abruptly from 

 the rostrum, as in Atophyrax. 



Number of representatives. — Three members of the subgenus Weo- 

 sorex have been described: (1) pahistris, from the region between the 

 Eocky Mountains and Hudson Bay; (2) navigator^ from the Eocky 

 Mountains and Sierra Nevada; and (3) alMharMs, from the mountains 

 of northern New England and northern New York. Still another 

 species, Sorex hydroclromus Dobson, from Unalaska Island, is here 

 referred to Neosorex, though I have not seen specimens, and its exact 

 affinities are uncertain. 



SOREX (NEOSOREX) PALUSTRIS Rich. 

 (PI. X, figs. 5-7.) 



Sorex 2)alusirts Richardson, Zool. Jour., Ill, No. 12, p. 517, January to April, 1828. 



Type locality. — Marshy places from Hudson Bay to the Eocky Mts. 

 Geograplm disfribution.—Fnrts of the Boreal zone from Minnesota 

 to the east base of the Eocky Mountains. 

 Habitat. — Streams, lakes, and marshes. 



General characters. — Size very large (total length, 155 mm. or more; 

 hind foot, 19 to 20 mm.); tail long; coloration of body and tail sharply 

 bicolor; unicuspids broad. 



Co?or.— -Upper x^arts dusky, finely mixed with hoary; under parts 

 dall white, sometimes clouded across breast and in anal region; tail 

 sharply bicolor : blackish above and all round near tip, white below, 

 the white narrower than the black; feet dark on outer side, whitish on 

 inner side. 



Cranial and dental characters. — (Specimen No. 69177, S ad., from South 

 Edmonton, Alberta). Skull large (22.5 by 10.2 mm.); brain case ele- 

 vated decidedly above plane of rostrum; palate and postpalatal notch 

 rather broad. Molariform teeth large and heavy, deei)ly excavated pos- 

 teriorly. Unicuspidate teeth only slightly imbricating, the first and 

 second subequal and very broad (transverse diameter equal to or greater 

 than anteroposterior) ; third abruptly very much smaller; fourth much 

 larger than third and about two-thirds size of second. 



Measurements. — Eichardson's measurements of the species are: Total 

 length, 155 mm.; tail vertebras, 65.5 mm.; hind foot, 19 mm. A speci- 

 men from Edmonton, Alberta, collected by J. Alden Loring, measured 



