1915.] Allen, Review of the South American Sciuride. peek 2i1 
of the upper surface washed lightly with orange yellow, the black subbasal 
portion of the hairs strongly visible at the surface, the base of the hairs 
apnulated with pale buff; tail below almost wholly intense black for the 
proximal half, the distal half grizzled black and pale orange yellow, black 
predominating, and narrowly fringed with pale orange yellow. One of the 
two topotypes is like the type, in the other the hair tips of the upperparts 
and the fringe of the tail are a little deeper tone of yellow. 
“Total length (type), 560 mm.; head and body, 270; tail vertebree, 290; 
hind foot, 65. The lateral hairs of the tail are fully 75 mm. long, and when 
the hairs are directed laterally give a breadth of fully 6 inches,— about one 
third greater than in S. tricolor or in any member of the langsdorffii-igni- 
ventris-pyrrhonotus group. 3 
“Skull (type), total length, 66; zygomatic breadth, 38; interorbital 
breadth, 20; postorbital breadth, 19.3; breadth of braincase, 25; nasals, 
22 X 8.2; diastema, 19; maxillary toothrow, 10. Rostrum relatively long 
and narrow.’’— Allen, J. ¢. 
Specimens examined, 3.— Venezuela: Southern base of Mt. Duida, type 
and 2 topotypes (Am. Mus.). 
Remarks.— In the form of the skull Sciurus duida closely resembles S. 
tricolor, especially in the narrow, slender, and relatively long rostrum, but 
it has no near resemblance to that species in coloration or texture of pelage, 
in which it most resembles the zgniventris group, with which, however, the 
form of the skull denotes no close relationship. A striking feature of this 
species is its magnificent tail, which is fully one third broader than that of 
any other South American squirrel. 
Urosciurus igniventris igniventris (Wagner). 
Plate XIV, Figs. 3, 4. 
Sciurus igniventris WAGNER (ex Natterer, MS.), Wiegmann’s Arch. f. Naturg., 
1842, I, p. 360; Abhandl. math.-phys. Classe, K.-B. Akad. Wissen. Miinchen, Als 
1850, p. 275.— Auten, Mon. N. Amer. Rodent., 1877, pp. 768-773 (part, only the 
reference to S. igniventris Wagner).— Tuomas, Ann. and Mag. Nat. Hist. (7), VI, p. 
137, July, 1900, part (Nericagua and Munduapo, Upper Orinoco; not the Bogota 
specimens = S. 7. tedifer Thomas, 1903). 
Sciurus morio Waaner, Abhandl. math.-phys. Classe, K.-B. Akad. Wissen. 
Miinchen, V, 1850, p. 275 (a melanism of S. igniventris). 
Sciurus variabilis ALLEN, Mon. N. Amer. Rodentia, 1877, p. 768, part.— ALSTON, 
Proc. Zool. Soc. London, 1878, p. 665, part. 
Type locality— Maribitanos, Upper Rio Negro, Brazil. 
Geographic distribution.— Upper Rio Negro and Upper Orinoco, west in 
Colombia to base of Eastern Andes. : 
