ALLEN: mammalia: mustelid^. 145 



ish above, with a broad, ill-defined subterminal band of blackish and 

 tipped with white ; below with two indistinct bands of black ; claws white, 

 fore claws very long. 



This is a very old female, as shown by- the skull. Two younger speci- 

 mens are similar, except that the dark median dorsal band is blackish 

 brown instead of chestnut, and the sides, underparts, and limbs are also 

 much darker, almost black. A third somewhat older specimen is rather 

 lighter, with a faint tinge of chestnut on the median band and sides. It 

 would thus appear that the general color lightens with age, and that the 

 light brown tints characterize more particularly old adults, which some- 

 times have the median band light chestnut and the upper portions of the 

 sides of the body chestnut brown. 



The tail, in all of the specimens, is composed of two kinds of hair, as , 

 respects length and color — long hairs wholly white, and shorter hairs with 

 the apical portion black, which latter form the subapical black band of the 

 tail, beyond which the tips of the wholly white hairs project for about 30 

 to 35 mm., forming a broad terminal white fringe. In the old specimen, 

 described above in detail, there are two broad black bands in the tail, a 

 subapical and a subbasal, both distinctly visible on the lower surface of the 

 tail, but only the outer one well defined on the upper surface. A close 

 examination shows that both bands, while quite regular and well defined as 

 seen from below, are composed of hairs that are white basally and black api- 

 cally, those forming the proximal band being only about half the length 

 of those which constitute the subapical band. They are probably a new 

 set of hairs, growing out to replace the longer ones. 



Measurements.— 0\d. female (No. 99270, U. S. Nat. Mus., Rio Gallegos, 

 Jan. 18) : Total length, 570 mm.; tail vertebrae, 200; hind foot, 56; longest 

 fore claw, 18 ; lateral tail hairs, 140-150. Milne-Edwards gives the length 

 of the type of Couepatus castaneus as: Head and body, 360; tail 180 

 (= total length, 540) ; hind foot 50; and of his Santa Cruz specimen as : 

 Head and body, 410; tail, no (= total length, 520); hind foot, 60. 

 Skull: Total length, 64; basal length, 60; zygomatic breadth, 42.4; 

 mastoid breadth, 34.3; postorbital constriction, 17; palatal length, 25.3; 

 post-palatal length, 29 ; length of nasals, 20 ; width of nasals at middle, 

 6; upper premolar-molar series, 15.4; m', transverse, 8; antero-posterior, 

 6.5; lower jaw, length, 4L5 ; height at coronoid, 21; lower premolar- 

 molar series, 20. In this skull the teeth are very much worn, but there 

 is no sagittal crest. 



