178 U. 8. P. R. R. EXP. AND SURVEYS ZOOLOGY GENERAL REPORT. 



Fison weasel, PENNANT, Hist. Quad. 1781, No. 205. IB. Arctic Zool. I, 1784, 78. 

 Lesser otter, PENN. Hist. Qaud. 1781, No. 228. 

 Jtfinx, PENN. Arctic Zool. I, 1764, 87. 



g p . CH. Tail about half as long as the body. General color, rather dark brownish chestnut. Tail nearly black. End of 



chin white, but not the edge of the upper jaw. 



The well known mink of the United States is so much like an otter in appearance as to merit 

 the name of lutreola, equally well with its Old World representative. It is, however, a true 

 weasel, although in many points quite different from the smaller and more slender ermines. 



(No. 1154.) The head of the mink is broad and depressed, quite abruptly truncated anteriorly, 

 with the corners rounded. The naked muffle is a little broader than high above, about twice 

 the width of the septum. 



The whiskers are long and rigid, arranged in four horizontal series, with a fifth less distinct 

 in the edge of the upper lip. There are several stiff long hairs behind the angles of the mouth, 

 as well as under the chin, opposite the centre of the skull. The eye is small, the centre half 

 way between the nose and the anterior border of the meatus. The ears are not so large as in 

 the ermines, rather longer than high, entire, except the lower half of the posterior margin, 

 which is split into two laminae ; both surfaces are rather thickly coated with hair. 



The feet are large and broad, the anterior quite as broad as the hinder, but not so long. On 

 the fore foot the third toe is longest ; the fourth but little shorter ; then the second ; the fifth is 

 intermediate between the first and second. In the hind foot the third and fourth are nearly 

 equal ; the second and fifth also equal, but shorter ; the first shortest. All the toes are webbed 

 at their bases, this extending farthest along between the third and fourth. 



The balls of all the toes are naked and not at all overgrown with hairs, making five on each 

 foot. Behind these, under the metacarpus and metatarsus, are four others placed, respectively, 

 at the bases of the digits; one of these, larger than the rest, situated at the line of junction of 

 the third and fourth digits. On the fore foot is an additional pad near the outer edge, behind 

 the outer matacarpal pad, separated from it by hairs. There are narrow valleys between the 

 pads on the palms and soles, but no hairs, so that when stretched apart all appear as one naked 

 space. To sum up, in a word, there are nine naked balls on the hind foot, and ten on the fore 

 foot. The under surfaces of the feet are well furred around these pads, except as described. 

 The tail is rather long and conical, tapering gently to the tip. Including the hairs, it is about 

 equal to half the length of head and body. There is a soft close under fur, with longer, coarser, 

 and very lustrous hairs intermixed. This is seen on the tail as well as the body. 



This species is all over of a nearly uniform chestnut brown, not appreciably lighter beneath ; 

 the tail is considerably darker ; the end of the chin is white, as also a spot between the fore legs. 



There is a great difference in the size of different specimens of this animal, and the gradations 

 between the extremes are so gentle in this respect, as well as in color, as to render it very difficult 

 to establish more than one species. Thus among the skins before me are two of very large size 

 the one from near Vancouver's island, (1025,) the other from the upper Missouri, (1755,) in 

 which the entire pelage is a light yellowish brown, the feet of the same color, and the end of 

 the tail only a little darker. The body appears to have been almost as stout as that of an otter. 



Some specimens have a slight tinge of gray in the chestnut, others are redder than the first 

 one described. In nearly all there is a white patch on the end of the chin, and others on the 

 throat, belly, or between the legs. Occasionally, however, a specimen is met with in which 



