OCR Text |
Show 1888.] MAMMALS OF CHRISTMAS ISLAND. 533 a. 8. b. 8. c. 2- d. 2- Head and body. millim. . 235 . 235 . 240 . 222 Tail. millim. 246 253 257 267 Hind foot. millim. 50 50 49 50 Forearm and hand. millim. 67 67 66 70 Ear. millim. 17'5 17 17*5 16-7 Heel to front of last food-pad. millim. 25 25-5 25 26 Mr. Lister's numerous specimens of this species agree very closely with one another and with the type, the only point in which they vary being in the degree in which the under surface is white or brown. All the females have the mammary formula 1 - 1 = 4 . 4. Mus NATIVITATIS, sp. 2 specimens. Head and body. millim. a. d(type) 254 b. 8 264 Tail. millim. 176 175 n. Hind foot. millim. 54 54 Forearm and hand. millim. 66 65 Ear. millim. 20x17 18 x 17 Heel to front of last foot-pad. millim. 26-6 27-3 Skull.-Basal length 46*8, greatest breadth 24-8 ; nasals, length 20'5; interorbital breadth 8*7; interparietal, length 7'1, breadth 12*5; infraorbital foramina-length of outer wall 4*1, breadth from outer corner of one to that of the other, 134 ; palate-length 26*7, breadth outside m.1 9*0, inside m.1 4*5 ; diastema 15-5; length of anterior palatine foramina 9'3 ; length of upper molar series 7'6. Lower jaw-length (bone only) 30, (to incisor-tips) 34*6, greatest height, obliquely, from coronoid to angle, 15. Size large ; form thick and clumsy, the limbs and tail stout and heavy, but the head peculiarly small, slender and delicate. General colour dark umber-brown all over, the belly not, or scarcely, lighter than the back. Ears small, laid forward they barely reach to the posterior canthus of the eye. Fur of back long, thick, and coarse, but without the extremely long piles so characteristic of M. macleari, the longest hairs being about 40 or 45 millim. in length. Hands and feet very thick and heavy ; the claws, especially on the fore feet, enormously broad and strong, not compressed, more than twice the size of those of M. macleari, and evidently modified for burrowing. Palms and soles naked, smooth ; the pads broad, low, and rounded, unusually little prominent; last hind foot-pad elongate. Tail shorter than the body without the head, very thick, evenly tapering, nearly or quite naked ; its scales triangular, very large, the rings averaging about 7 or 8 to the centimetre1; its colour uniform blackish brown throughout, above and below, the white skin, however, showing to a certain extent between the scales. Skull disproportionally small, light aud delicate; compared with that of M. macleari it is slightly shorter and very considerably narrower. 1 10 to 12 in M. macleari. |