Four new South-American Mammals. 219 
The skin on which this species is founded is that men- 
tioned under “ Hesperomys (Habrothrix) axanthorhinus” in 
my account of the ‘ Alert’ collections (P.Z.8S. 1881, p. 5). 
That determination was based mainly on the spirit-specimen 
referred to at the same time, which is undoubtedly a true 
Akodon (= Habrothrix). A comparison of the skulls now 
shows not only that the two, like as they are externally, are 
different as species, but that the Monteith Bay skin belongs 
to the Oxymycterus group, as is especially shown by its 
narrow slanting zygoma-root, slender muzzle, and broad 
brain-case. In that group no species as yet described bears 
any resemblance to it. 
Dasyprocta Kalinowskit, sp. n. 
Size rather large. Fur ringed with black and yellowish 
rufous, the elongated hairs of the rump white with black 
tips, contrasting markedly with the rest of the body. Area 
round the root of tail black, abruptly defined from the white 
erest-hairs. Under surface yellowish, grizzled with brown. 
Feet blackish. Tail about an inch in length, naked. 
Skull elongate, not unlike that of D. vartegata and fult- 
ginosa, but with the muzzle rather broader and more trumpet- 
shaped. 
Dimensions of the type, an adult male :— 
Head and body (measured in flesh by collector) 6°30 
millim.; hind foot 125. 
Skull: basilar length 89, greatest breadth 54; nasals 
46x22; interorbital breadth 33°5; diastema 380; upper 
molar series 20°5. 
Hab. Idma, Valley of Santa Ana, Cuzco, Peru. Alt. 
4600 ft. Coll. J. Kalinowski, Nov. 2, 1894. 
‘This handsome Aguti may be readily distinguished from 
any species hitherto described by the peculiar coloration of 
its long rump-hairs, which, white with black tips, are quite 
unlike those of any other species. 
It was obtained by, and is named in honour of, Mr. J. 
Kalinowski, the well-known Polish collector, to whom 
science is already indebted for the discovery of so many 
interesting Peruvian mammals. 
Peramys adustus, sp. n. 
Size smal]. Fur close and short, only about 4 millim. long 
on the back. Colour all over above uniform finely grizzled 
brown, with a slight yellowish tinge; tip of muzzle blackish. 
Under surface coloured about as in Jus musculus ; line of 
demarcation on sides little marked. ars very short, prac- 
tically naked. ands and feet greyish brown, digits naked. 
Tail practically naked, its few fine hairs black. 
