MAMMALS SORICINAE SOREX PLATYRHINUS. 25 



SOREX PLATYRHINUS. 



Otisorex platyrkinus, DEKAY, N. Y. Zool. I, 1842, 22 ; pi. v, f. 1. 

 Sorex platyrhynchus, LIXSLEY, Sill. Am. J. Sc. XLIII, 1842, 346. 

 Sarex platyrhinus, WAGNER, Suppl. Schreb. V, 1855, 547. 

 Sorex forsteri, GAPPER, Zool. Jour. V, 1830, 201; pi. vii. 

 THOMPSON, Nat. Hist. Vermont, 1842, 26. 



SP. CH. Ears large and conspicuous. Tail scarely longer than the body, and only scantily provided with hair. Upper 

 premolars imbricated anteriorly; and decreasing gradually in size. Color above, chestnut or dark brown ; beneath, pale 

 cinerous. Length, over two inches. Tail scarcely exceeding 1J inch. 



(No. 1694.) This very diminutive and slender shrew has an exceedingly attenuated and 

 elongated muzzle, which, however, is depressed towards the naked and bilobed tip. Viewed 

 from above, there is a slight contraction in the outline of the head, a little anterior to the eye, 

 beyond which it swells out again, before tapering to the end. The width of the head is about 

 half its length, or a little less. The end of the lower incisor falls about midway between the 

 tip of the nose and the eye, which is quite large for a shrew, and distinctly visible without a 

 glass. It is situated about halfway between the tip of the nose, and the anterior base of the 

 external ear. 



The whiskers are numerous and thickly set ; they are black, and the longest reach back nearly 

 to the occiput. 



The ears are very large, (for American shrews,) and generally distinctly visible, though 

 scarcely projecting beyond the fur. The internal ear is widely open, and the concha is directed 

 backwards, as in the genus Mus. The antitragus is very large and semi-circular, and fits closely, 

 like a valve, over the meatus, protecting it from the admission of water ; when this is closed, 

 however, the rest of the ear is distinctly visible. The concha is semi-circular in shape ; its upper 

 and lower roots about 0.21 of an inch apart, or the distance from incisors to tip of muzzle ; the 

 meatus occupies only the lower third of this distance, and the upper root of the concha does not 

 extend beyond the posterior margin of the meatus. There is a vertical partition or flap of skin 

 extending across the concavity of the ear corresponding to the helix, which, however, does not 

 rise as high as the margin of the concha. The convexity and edge of the ear are rather thickly 

 covered with hairs, as also the edges of the antitragus and internal flap ; the remaining portions 

 are naked. The greatest distance from the lower root of the concha to its most remote point is 

 0.29 of an inch, or about the distance from the root of the concha to the eye. 



The feet are moderately large ; the anterior about as broad as the posterior, and about 0.55 

 their length. The fore and hind claws are about equal. The under surfaces of the feet are 

 naked, the hinder ones with small tesselated tubercular plates, and the larger tubercles opposite 

 the middle of the metatarsus. Besides these, there are four other large tubercles at the bases of 

 the first, second, and fifth toes, and between the bases of the third and fourth. 



The hair on the back is about 0.20 of an inch long. The tail is long ; without the hairs, it 

 reaches to the meatus, or is about as long as the body ; it is cylindrical, somewhat thickened 

 towards the middle, closely annulated, and with hairs springing between the annuli, and 

 extending over about three of the latter ; it is terminated by a pencil of long hairs. 



The upper parts are of a rather light chestnut brown, with a hoary aspect, owing to the tips 

 being abruptly of this color, but a little lighter penultimately. The under surfaces are grayish 

 4L 



