2 20 NEW GENUS AND SPECIES OF THE SORECID^. 



in Other respects, is to have the 'third premolar' decidedly smaller 

 than the ' fourth ; ' while in all the species east of the Rocky 

 ^Mountains (with one possible exception), the same tooth is as large 

 as or larger than the other. Of the fact there is no question ; it 

 may be observed in an instant, and is unmistakable." * 



But Bendire's Shrew, though an inhabitant of the Pacific prov- 

 ince, has the third and fourth unicuspids of approximately equal 

 size, presenting, in this respect, a curiously exceptional condition. 



In the type of Ncosorex navigator the ratio of the length of the 

 hind foot to the head and body is 36, in the present species it is 26, 

 and in Sorcx Cooperi 21. In Bendire's Shrew the proportions of 

 the feet differ from those of any known species, agreeing better 

 with Neosorex than with any other member of the family. The fore 

 feet are large and broad, measuring 1 1 by 4 mm.; the hind feet are 

 very long and comparatively slender, measuring 20 by 3.5 mm. 

 The fore feet much resemble those of the Blarina brcvicauda, but 

 the hind feet are both relatively and absolutely much longer. Thus, 

 arranp-ino- the described American Shrews accordinor to the leng-th 

 of the hind foot, Blarina would stand at one end of the series and 

 Neosorex at the other, the various species of Sorcx coming next 

 after Blarina, and the present species next before Neosorex. The 

 feet are moderately fimbriate, but not to the extent seen in Neo- 

 sorex ; still, the fimbriation is sufficient to indicate a non-fossorial 

 habit. 



The tail is almost as long as the head and body. In N'eosorex 

 it is given as "about equaling or exceeding the head and body." 

 In coloration it differs widely from Neosorex, being unicolor instead 

 of bicolor. 



In comparing it with the genus Sorex it is necessary to consider 

 only the subgenus Sorex proper, with which it agrees in the pos- 

 session of thirty-two teeth. It is found to differ from this subgenus, 

 as restricted by Coues, in the following particulars : 



* Bull. U. S. Geol. and Geog. Survey, Vol. Ill, No. 3, 1877, p. 637. 



