MAMMALS-SORICINAE. 
9 
incisor as large as tlio fix*st 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., Y, 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, ^ ~ ^ = 32. 
B. Feet small; teeth, iEi + ^ = 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, \ -f- — + ^ = 32. 
B. Bi-colored; teeth, -f- ^ = 30. 
In the first division there are probably two species to be ranged: Neosorex navigator and Sorex 
Jimbripes 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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