212 VERTEBRATE ANIMALS OF THE UNITED STATES 



Family 2. Soricidae. — Shrews. Body rather slender; neck dis- 

 tinct; snout elongate and proboscis-like; eyes and external ears normal, 

 but small; feet pentadactylous, the fore feet not modified; fur soft and 

 silky; zygomatic arch of skull wanting: many species, which are found 

 throughout the world, except in the Australian and South American 

 regions; about 36 species and 6 genera in the United States. The 

 shrews are among the smallest mammals. They live in shallow tunnels, 

 in run-ways in moss and mold and under logs and brush, feeding on 

 worms, grubs, snails, mice and other small animals, including one 

 another, and are noted for their fierceness and voracity. They raise 

 two or more litters of 6 to 10 each during the summer and fall, and do 

 not hibernate. 



Key to the United States Genera of Soricidae 



ai Tail long, being much longer than the head (Fig. 146). 



bi Body 100 mm. to 130 mm. long i. Sorex. 



hi Body about 150 mm. long 2. Neosorex. 



bs Body about 85 mm. long 3. Microsorex. 



ao Tail short, being usually shorter than the head (Fig. 147). 



bi Teeth 32; size large , 4. Blarina. 



b2 Teeth 30; size small 5. Cryptotis. 



bs Teeth 28; size small 6. Notiosorex. 



I. Sorex L. Long-tailed shrews. External ears well developed, 

 generally appearing above the fur and directed backwards; tail about as 



fi^ 



a b 



Fig. 145. — Upper jaw of Sorex personatiis: o, lateral view; b, lower surface {from Merriam). 



long as the body; dentition 4/2, i/o, 2/1, 2>/^: over 50 species and 

 subspecies in the United States and Canada. 



5. personatus GeofTroy. Common shrew (Fig. 145). Body brown 

 above, gray beneath; length 100 mm.; tail 38 mm.; hind foot 12 mm.: 

 New England to Alaska; southward to southern Pennsylvania, Tennessee 

 and Northern Nebraska, and in the higher Alleghenies into North 

 CaroHna; not in the southern Rockies and the Cascade-Sierra systems; 

 Boreal and Transition zones; the commonest species. 



S . fontinaUs Hollister. Like S. personatus, but with a much shorter 

 tail: District of Columbia and its neighborhood. 



