MAMMALS SORICINAE. 9 



incisor as large as tho first of the five premolars ; lower incisors dentate on the cutting edge ; 

 teeth colored at the points ; tail moderately long, with the hairs all equal. 



3. CROCIDURA, Wagler. Teeth, 28 or 30 ; the posterior hook of the upper incisor smaller 

 than the first premolar ; premolars, three or four ; lower incisors with even cutting edge ; all 

 the teeth white ; tail with longer scattered hairs interspersed indiscriminately among the 

 short ones. Wagner, in Suppl. Schreb., V, 1855, 564, recognises a fourth genus, Myosorex, of 

 Gray, as characterized by the dentition of Crocidura, three premolars, and the tail clothed with 

 short hairs, without larger ones interspersed. The species, M. varius, is a native of S. Africa. 



Of the above genera, but one, Sorex, (Amphisorex, of Duvernoy) is found in North America. 

 Crossopus is represented by a genus differing in having a greater number of premolars and 

 a differently constituted tail. Nothing essentially similar to Crocidura has been yet detected. 



Of the American species there may be established three genera ; two of them possibly 

 divisible into two sub-genera, according as there are five premolars in the upper jaw or 

 only four, this difference being accompanied by others of more or less importance. Their prin 

 cipal characteristics are as follows : 



1. NEOSOREX. (n. g.) Ears rather short, partly furred on both surfaces, valvular, concha 

 directed backwards ; tail longer than the body (and head,) all the hairs of equal length, except 

 at the tip ; feet very large, with a fringe of ciliated hairs ; skull very slender anteriorly, and 

 elongated ; upper anterior incisor with a second basal hook, and a small process on the inner 

 side near the point. Two first premolars rather larger than the next. 



2. SOREX. Ears large, valvular, partly furred on both surfaces, concha directed backwards ; 

 tail about as long as the body; the hairs of equal length, except at the tip ; feet moderate, not 

 fringed ; skull slender anteriorly and elongated ; upper anterior incisor with a second basal 

 hook, and a small angular process on the inner side near the point ; two anterior premolars 

 somewhat larger than the next. 



A. Feet large ; teeth, }=J -f + ~ 3 = 32. 



B. Feet small ; teeth, j=| -f g + 5 = 30. 



3. BLARINA. Ears small, not visible in nature ; concha directed forwards, closing the meatus, 

 its concavity entirely naked ; tail as long as the head, or shorter ; feet moderate, not ciliated ; skull 

 rather thick anteriorly, and shortened ; upper anterior incisor without a basal hook, but only 

 one acute lobe, nor has it any process on the inner side of the point ; first two upper premolars 

 lateral, much larger than the next. 



A. Nearly uni-colored ; teeth, -^ -J- ^ ~+~ 3^3 ^2. 



B. Bi-colored; teeth, -f- 2=2 H~ 5=5 == 30 - 



In the first division there are probably two species to be ranged : Neosorex navigator and Sorex 

 fimbripes of Bachman. As stated, the genus differs from Crossopus in all respects except in the 

 fimbriated or ciliated feet. 



The genus Sorex embraces a large proportion of the American species, and is equivalent to 

 the Amphisorex of Duvernoy, and Otisorex of Dekay, the latter established on the 0. platyrhinus. 

 The European species have invariably five premolars above, which diminish gradually from the 

 first to the fifth. As will be seen, two species have but four premolars, this character accom 

 panied by smaller feet. This group and the preceding have the upper jaw narrower and longer 

 than the next, the greater elongation being due to the larger size of the third and fourth, or 

 third, fourth, and fifth premolars ; these are but little less than their predecessors, instead of 

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