216 Mr. O. Thomas on some small 
readily presumed that specimens from one end of the district — 
are distinct as a matter of course from those described from 
the other—a presumption which, allowing for the great 
difference in altitude and position, would in other parts of — 
America generally be quite justifiable. 
4. Akodon Spegazzini, sp. n. 
a, 6. Lower Cachi. 
c. Pampa Grande. 
A medium-sized Akodon of a generally fulvous colour, 
above and below. 
Size rather smaller than A. olivaceus. Fur fairly long, 
soft and woolly ; the underfur about 10 mm. long on the back. 
General colour dull grizzled fulvous rufous, quite unlike that 
of the greyish Akodons of the olivaceus group. Longer hairs 
as usual black. Fulvous body-colour clearer on sides, and 
passing almost unaltered on to the belly, which is scarcely 
lighter than the flanks ; hairs round the anal region brighter 
fulvous. Throughout, above and below, the basal three 
fourths of the hairs are dark slate-coloured. ars fairly 
large, rounded, laid forward in a spirit-specimen they reach 
about 2 millim. short of the posterior canthus; well clothed 
with short fulvous hairs. Hands and feet pale whitish 
fulvous above; claws long and strong, but not exaggerated as 
in the A. megalonyx group. Palms and soles naked, with the 
pads 5-6 as usual; fifth hind toe without claw reaching to 
the end of the first phalanx of the fourth. Mamme 2—2=8. 
Tail rather long for an Akodon, finely haired, blackish above, 
yellowish white on the sides and below. 
Skull strongly built, though the zygomata are not very 
widely expanded. Nasals long, rather narrow. Interorbital 
region smooth, slightly convex, its edges square but not 
ridged. Interparietal very small, narrow from before back- 
wards, almost as broad laterally as in the middle line. 
Palatine foramina large and open, reaching backwards past 
the middle of m'. Posterior narial fossa narrow, the palatal 
edge nearly a millimetre behind m°. 
Incisors dark orange above, pale yellowish below. Molars 
strictly Akodont. 
Dimensions of the type, measured in spirit before skinning 
(female) :— 
Head and body 92 millim.; tail 71; hind foot, without 
claws, 20; ears 14, (The inclusion of the claws would increase 
the hind foot measurement by about 2°5 millim.) 
Skull: basal length 22°5, basilar length from henselion 
20:5; nasals 9°6x 3; interorbital breadth 4°5; interparietal 
7x14; palate length from henselion 11°3; diastema 7:2; 
; 
1 
