“Very common in long dry grass in the valleys of Port Desire.”—D.
The skull is figured in Plate 33, fig. 5, c. Fig. 5, a. represents the molars of the upper jaw; fig. 5, b. those of the under jaw, and fig. 5, d. represents the posterior molar of the under jaw when more worn.
It was with some hesitation that I described this as a distinct species in the Society’s Proceedings. I have now re-examined the specimens, and still am unable to satisfy myself whether they are varieties of Mus xanthorhinus or not. Both of Mus canescens and of Mus xanthorhinus, I have before me what I imagine to be an adult and a young specimen. The adult and the young of M. xanthorhinus agree in being of a yellowish brown colour, and in having the muzzle and tarsi deep yellow; both specimens of Mus canescens are of a gray colour, with an indistinct yellow wash, the muzzle and tarsi being tinted with yellow, as in M. xanthorhinus. Besides this difference in tint, which, perhaps, is unimportant, M. canescens differs from M. xanthorhinus in having the head larger, the tail rather longer, and the fur less soft. The specimens of this animal are both from Patagonia; one of the specimens of Mus xanthorhinus was brought by Mr. Darwin from Terra del Fuego; and as the other formed part of Captain King’s collection, it in all probability came from the same locality. As I only possess one skull, I cannot speak with certainty as regards the size of the head; the difference, however, in the stuffed specimens is considerable, and it is strange that each of the pairs should agree so perfectly, supposing the difference to be the work of the stuffer’s hands.
18. Mus longipilis.
Plate XVI.
Mus longipilis, Waterh., Proceedings of the Zoological Society of London for February 1837, p. 16.
M. suprà obscurè griseus, flavo lavatus; subtùs griseus; pedibus fuscis, unguibus longiusculis; auribus mediocribus; caudâ corpore breviore, suprà nigrescente, subtùs fuscescente; rhinario sub-producto: vellere longissimo, molli.
Description.—Fur very soft and silky, and extremely long—the ordinary fur of the back measuring nearly three quarters of an inch, and the longer hairs one inch in length; ears moderate; tail nearly as long as the body; muzzle much pointed; general colour gray, washed with yellow, the under parts pale gray, or grayish white; feet brown; ears and tail well clothed; the hairs on the inner side of the ears are chiefly of a yellow colour, those on the upper surface of the tail are brown-black, those on the under part are dirty white; the hairs of the back are deep gray at the base, broadly annulated with yellow near the apex, and dusky at the apex; the longer hairs are grayish black; the hairs of the moustaches are dusky at the base, and whitish beyond that part; the claws are long, and but slightly curved; the incisors are slender; those on the upper jaw are yellow, and those of the under yellow-white.
| In. | Lines. | ||
|---|---|---|---|
| Length | from nose to root of tail | 5 | 4 |
| of tail | 3 | 4 | |
| from nose to ear | 1 | 2 | |
| of tarsus (claws included) | 1 | 0½ | |
| of ear | 0 | 6½ |
Habitat, Coquimbo, Chile, (May.)
This mouse is remarkable for the great length and softness of its fur, even among the species here described, most of which have very loose, long and soft fur.