180 Onanew Mountain Vizcacha from Patagonia 
examples of a Lagidiwm, a form which Sr. Budin did not 
obtain in this region. 
It proves to be distinct from L. morent, the only North- 
Patagonian form as yet described, and may be called 
Lagidium bowt, sp. n. 
Greyish olive, the under surface slightly washed with 
yellowish. Feet dark. 
Size about as in L. moreni. General colour above darker 
and more suffused with yellowish than in moren?, the colour 
not so clear a grey. Under surface also greyish olive, the 
hairs lightly washed with dull yellowish, markedly different 
from the strong yellow of morend; but the genital area is 
more definitely yellow, forming a marked patch. Dorsal 
stripe more strongly developed than in moreni, running from 
nape torump. White axillary patches present. Hands and 
feet comparatively dark—dark grizzled grey-brown, very 
different to the greyish white of morenz. 
Skull, as compared with that of moreni, with shorter 
broader muzzle, the nasals more inflated. Premaxillary pro- 
cesses less surpassing the nasals behind. Suprameatal island 
on top of skull narrowly oblong, not so square. Anterior 
palatine fissure very small, half the length of that in morenz; 
palatine foramina shorter, their posterior end narrowed by 
sharp inturned edges. Molars stouter and heavier, a dimen- 
sion taken at right angles to the line of the lamine definably 
greater ; in p* of the type, for instance, this dimension 1s 
5-4 mm., while in the type of morenz it is 4°6. 
Dimensions of the type (measured in flesh) :— 
Head and body 490 mm.; tail 320; hind foot 105; 
ear 68. 
Skull: greatest length 91; condylo-incisive length 83°5 ; 
zygomatic breadth 48°5 ; nasals 34x 13°5; anterior palatine 
fissure 3°43; palatine foramina 15; upper tooth-series 
(crowns) 21. 
Hab. Pilcafieu, Upper Rio Negro, N.W. Patagonia. Type 
from 1200 m. 
Type. Adult female. B.M. no. 20. 11.4. 95. Original 
number 200. Collected 9th April, 1920, by H. E. Box. 
Presented by Oldfield Thomas. ‘Two specimens obtained by 
Mr. Box, and an additional skin and three skulls presented 
by Mr. Guy H. Dawson of Pileafieu. 
To this species I refer not only the specimens now come, 
but one which was received in 1899 from the La Plata 
Museum, and was hitherto believed to be referable to 
L. morenit. Theadditional material, however, shows that the 
, 
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