266 The Mammals of Colorado 
case being depressed to plane of rostrum ; palate narrow . The small 
flat skull distinguishes this species from the other three thus far 
recorded from Colorado. The species which approaches it nearest in 
size, 5". personatus, has a slightly longer hind foot and has the third 
unicuspid tooth larger than the fourth instead of vice versa as in 
case of nanus. 
Distribution. — The Dwarf Shrew has been reported from Montana 
and Colorado only. In the latter State it has been taken at Estes 
Park, Westcliffe, and near Colorado Springs, betw^een 7,000 and 
8,000 feet elevation. 
Genus NEOSOREX (Grk. neos, new + sorex) 
Neosorex Baird, Mammals N. Am., p. 11 (1857). Type Neosorex 
navigator Baird. 
Revision, Merriam, N. A. Fauna, No. 10 (1895). 
Shrews of large size, wdth long tails; feet large and fringed wdth 
bristle -like hairs; brain-case broad; mandible lightly built and 
slender. 
These animals are found usually about water, and are 
of semi-aquatic habits. This genus is confined to North 
America, being found in the Sierra Nevadas of California, 
the Rocky Mountains from Colorado northward, and the 
boreal parts of eastern North America from plains of North 
Saskatchewan to Minnesota, northern Pennsylvania, the 
Adirondacks of New York, northern New England, and 
eastern Canada on both sides of the St. Lawrence, and one 
species in Alaska. Elliot's Check-list gives five species and 
subspecies, one of which inhabits Colorado. 
Neosorex navigator (Lat. a sailor). Water Shrew 
Neosorex navigator Baird, Mamm. N. Am., pp. 11-12 (1857). 
Type locality. — Unknown, probably northern Idaho. 
Measurements. — Total length, 6.25; tail vert., 3; hind foot, 0.55. 
Description. — Upper parts plumbeous, finely mixed with hoary; 
under parts silvery white ; tail bicolor, dusky above and all around 
at tip, white below. Skull large; brain-case high, sloping from 
behind forward ; palate rather broad ; first and second unicuspidate 
teeth about equal in size; third and fourth also about same size 
but much smaller than first two. 
Distribution. — The Water Shrew is found from Lat. 54° N. 
