76 
U. S. P. R. R. EXP. AND SURVEYS—ZOOLOGY-GENERAL REPORT. 
UROTRICHUS, Temminck. 
Urotrichus, Temminck, Van der Hoeven, Tijdschr. V, 1838.— Ib. Mag. de Zool. 1842. 
Muzzle prolonged into a cylindrical tube, continued some distance beyond the incisors, terminating in a simple naked bulb. 
Nostrils cylindrical, opening in the side. Eyes and ears concealed. Tail long and hairy. Fore feet moderately large, shorter 
than the hind feet. Upper and under surfaces of both covered with small plates. 
In the above diagnosis I have the pleasure of first introducing a genus of insectivorous mam¬ 
mals into the fauna of North America hitherto only represented hy a single species, the U. 
talpoides, 1 from Japan. The specimen is, unfortunately, not quite mature, and the skull, with 
its dentition, is imperfect, so that I am obliged to rely upon Temminck for the dental formula. 
In external form this animal exhibits a close resemblance to Condylura, the only striking 
difference being in the much elongated and tubular muzzle, without radiations, and the nostrils 
lateral, not terminal. The feet, hands, and tail, are very similar. 
The dental formula, according to Temminck, is incisors, ; canines, kjj; molars,^ = 36, 
or, as there are three true molars, the latter quantity would he divided into: premolars ^,and 
molars The analogy of dentition would, however, make the formula more probably: incisors, 
canines, ; premolars, ^ j molars, ^ = ^ = 36. 
The genus Urotrichus in many respects resembles the shrews, and, in fact, may he considered 
as forming the connecting link between this family and the moles through Condylura. 
UROTRICHUS GIBBSII, Baird. 
Tail as long as the body (exclusive of the head). Color uniform dark sooty plumbeous. Body about 2| inches long. 
This animal, in many respects, hears a close resemblance to Condylura , as in color, feet, and 
tail, from which it is readily distinguished hy the much elongated muzzle and the absence of 
any radiated processes. The size is about that of Sorex carolinensis. 
The nose is much elongated and projects more beyond the incisors than in Sorex. Indeed, 
it is, for most of its length, a nearly cylindrical tube, scantily covered with short hairs, and 
terminated hy a naked bulb or glans, with the nostrils pierced in the sides. A distinct con¬ 
striction separates the bulb all round from the hairy portion of the nose. There is a slight 
furrow on the under surface of the muzzle. The eye and ear cannot he detected in the skin. 
They are said to he very minute in the Japan species, as in the moles. 
The hands and feet are constituted much as in Condylura, in having both surfaces tesselated 
with small isolated plates. These, on the upper surfaces of metacarpus and metatarsus, are 
thinly covered with long hairs, and in the hind feet, not restricted to the antero-external edge, as 
in Condylura. I do not find in the dry skin the peculiar scaphoid tubercle on the sole, so con¬ 
spicuous in Condylura. The hind foot is considerably longer (by two-thirds) than the fore foot, 
hut narrower. The hind claws are as long as the anterior ones, hut more straight, slender, and 
acute. The fore claws and hands appear less fossorial than in the other moles. The proportions 
of the digits differ from Condylura. Thus the 4th, 3d, and 2d, are successively a little shorter, 
See Temminck in Mag. de Zool. 1842, plate 55,. mammiferes. 
