FEB., 1912. MAMMALS or ILLINOIS AND WISCONSIN CORY. 409 

 KEY TO THE SPECIES. 



GROUP 1. Short- tailed Shrews. Ears completely concealed by fur; tail not ex- 

 ceeding one inch in length, usually decidedly less and always less than % 

 total length (nose to tip of tail). 

 SECTION 1. Total length more than 3.60 inches. 



General color dusky slate color, under parts only slightly paler; teeth 32; 

 four well developed unicuspid teeth, first two longer than third and 

 fourth, the third and fourth about equal; total length about 5 

 inches, averaging a little less; occurs in northern Illinois and Wisconsin. 



SHORT-TAILED SHREW OR MOLE SHREW. 

 Blarina brevicauda, p. 423. 



Similar to brevicauda but smaller; back sometimes faintly washed with 

 brown; teeth 32; total length about 4 inches; occurs from central 

 Illinois southward. CAROLINA SHORT-TAILED SHREW. 



Blarina b. carolinensis, p. 428. 

 SECTION 2. Total length less than 3.60 inches. 



Brown or iron-gray above, ashy on under parts; teeth 30; fourth upper uni- 

 cuspid exceedingly small and apparently absent, difficult to see 

 without a good lens and rarely visible from outside; occurs in Illinois 

 but not in Wisconsin. SMALL SHORT-TAILED SHREW. 



Blarina parva, p. 430. 



GROUP 2. Long-tailed Shrews.* Ears very small but visible, being not entirely 

 concealed by fur; tail more than one inch in length and always more than 

 J4 total length. 



SECTION 1. Total length less than 5.25 inches; feet not fringed. 

 PART. 1. Total length less than 4 inches. 



Upper parts dull chestnut-brown, approaching sepia brown; under parts 

 ashy gray, often washed with pale drab brown; tail usually less than 

 1.38 in. (35 mm.); hind foot .43 in. or less (n mm.); third unicuspid 

 tooth smaller than the fourth. CAROLINA SHREW. 



Sorex longirostris, p. 416. 



Upper parts approaching sepia brown; under parts ashy, gray or brownish 

 ash; tail usually more than 1.38 in. (35 mm.); hind foot about .47 in. 

 (12 mm.); third unicuspid tooth not noticeably smaller than the 

 fourth. COMMON SHREW. Sorex personatus, p. - 



Upper parts approaching sepia brown; under parts ashy gray or pale 

 brownish gray, often washed with buff on throat and breast; tail 

 less than 1.38 in. (35 mm.); hind foot .43 in. or less (n mm.); appar- 

 ently only 3 unicuspid teeth present, the 1st, 2d and 4th, the third 

 being so small and concealed between the others as to be seen with 

 more or less difficulty (cannot be seen at all without the aid of a strong 

 lens); "a distinct secondary cusp on the inner side of the canine and 

 second and third upper incisors" (Miller); occurs in Wisconsin and 

 probably in extreme northern Illinois. HOY'S SHREW. 



Microsorex hoyi, p. 418. 



* In all our Shrews the tail would be considered short. These are called Long- 

 tailed Shrews only by comparison with the very short-tailed species belonging to 

 the genus Blarina. 



