95 
jaw, directed nearly horizontally forward; the upper much curved, and 
forming a hook; the lower straighter, and with the cutting edges lobed. 
They are an abundant and widely distributed family, remarkablyevora- 
cious, feeding on worms, insects, and mollusks, sometimes destroying 
small vertebrates and readily devouring each other. They are chiefly 
nocturnal; some species of Neosorex are aquatic. The young, at birth, 
are naked and blind. None hibernate, but all are about in the coldest 
weather. _ | 
The Shrews are represented in America by three genera; Sorex (L.), 
the most generalized type, also occurring in the Old World; Neosores 
(Bd.) includes the Water Shrews, and is peculiar to North America, 
where it replaces Crossopus, of the Old World; Blarina, the most charac- 
teristic American genus, has no exact Old World analogue. 
All are small and difficult to study. Measurements of such small ani- 
mals are often fallacious. Color variation’, due to age, sex, season, or 
geographical distribution, have furnished data for worthless species ; 
moreover, the tail and lips, and possibly the feet, undergo extraordinary 
changes at the rutting season, so that such terms as “ pachyurus,” “ longi- 
rostris,” “ platyrhynus,” are of doubtful implication. Perhaps no family 
of North American mammals, of equal abundance, is so little known. 
Their nocturnal and subterranean life, combined with a shy and wary 
disposition and diminutive size, often baffles the attempt of the natural- 
ist to study their habits, or even to secure specimens of the known 
species. 
Contributions to our knowledge of American insectivora, since Profes- 
sor Baird’s treatise in 1857, are mainly due to Dr. Gill—“Synopsis of 
Insectivorous Mammals,” < Bull. U.S. Geol. and Geog. Surv., 2d ser., 
No. 2, pp. 91-120, May 14, 1875; to Mr. J. A. Allen—“ Catalogue of the 
Mammals of Massachusetts, with a Critical Review of the Species,” Bull. 
Mus. Comp. Zool., Cambridge, 1, No. 8, pp. 148~252, 1863; to Dr. Elliot 
Coues—‘ Precursory Notes on American Insectivorous Mammals, with 
Descriptions of New Species,’ in which several new sub-genera and 
species derived from Professor Baird’s MSS., written in 1861, are brought 
out, and other species described by Dr. Coues, based on material not at 
that time available. 
Genus BLaRINA Gray. 
1851. Blarina, Gray, Proc. Zool. Soc. Lond., 1851. (Type Sorez talpordes, 
Gapper.) 
Generic Oharacters:—Teeth 32 or 30 (75 sub-genus Blarina, Gray, emend. ; 
ts sub-genus Soriciscus, Coues). Hars small, the parts directed forward so 
