1915.| : Allen, Review of ine South American Sciuride. 245 
ward with morulus. While the average difference is appreciable, the two 
forms are not strongly differentiated, some of the specimens being not 
readily separable except by the labels. The dorsal band in choco is usually 
strongly developed and in some specimens is clear glossy black. The base 
of the tail is also darker, both above and below, and the black tip of the tail 
is longer and more intensely black. It intergrades to the southward in the 
Atrato district of northwest Colombia with M. gerrardi salaquensis, in which 
the black dorsal band is broader, the shoulders, thighs, and sides redder, 
and the black tail tip absent. 
Mesosciurus gerrardi salaquensis (Allen). 
Sciurus gerrardi salaquensis AuLEN, Bull. Amer. Mus. Nat. Hist., XX XIII, 
p. 592, Oct. 8, 1914. 
Type locality— Rio Salaqui, northwestern Colombia. 
Geographic distribution Known only from the drainage of the Rio 
Atrato. 
Description.— “Similar to S. gerrardi choco in coloration and other 
external features, but tail without a black tip, and sides of body more 
ferruginous. Upperparts with a broad median black band extending from 
the shoulders posteriorly over the proximal third of the tail - sides ochraceous 
lined with black; outside of fore limbs orange red, inside like the ventral 
surface; thighs and outside of hind limbs paler than shoulders and fore 
limbs; underparts deep orange red, with irregular blotches and lines of 
white (in type a large pectoral area, axillee, and a narrow median line white) ; 
tail above, proximal third black, rest bright red without black at the tip; 
under surface of tail for proximal third, and median area to end otf vertebree, 
grizzled ochraceous and black, distal two thirds and the tip broadly fringed 
with bright red. An adult female and a young female from the type locality 
are like the type.”’— Allen, J. ¢. 
Total length (type, from skin), 470 mm.; head and body, 240; tail 
vertebrae, 230; hind foot, 60. Unfortunately the skull is badly broken, 
but apparently presents no tangible differences from the skulls of neighbor- 
ing forms of the gerrardz group. | , 
Specimens examined, 7.— Colombia: Rio Salaqui, 3 (type and 2 
topotypes, Am. Mus.); Rio Atrato, 1, Nercua, a: (Nat: Mus... [See 
Addenda, p. 308.| 
Remarks.— Salaquensis intergrades with subspecies choco of eastern 
Panama. To the southward along the coast it evidently intergrades with 
true gerrardi, as shown by specimens from Baudo and Bagado, through the 
ereat increase in intensity of the red on the flanks and limbs. 
