284 Bulletin American Museum of Natural History. [Vol. XXXIV, 
Description.— Similar to S. stramineus stramineus but general coloration 
lighter, nearly as in S. s. nebouxi, from which it differs in having no nuchal 
patch of white. | 
Total length (from skin), 580 mm.; “head and body, 270; tail, 310; 
hind foot (wet), 57; ear (wet), 26.’’ — Thomas, I. ¢. 
Specimens ecamined, 0.— Ecuador: No specimens are at present avail- 
able for study, but the type and topotype were casually examined at the 
British Museum in April, 1913. 
Remarks.— In coloration, except in the absence of the white nuchal 
patch and the rufous wrists and ankles, guayanus closely resembles nebouxii, 
being much lighter colored throughout than true stramineus. It differs from 
zarume in the absence of a white nape patch and in gray instead of rufous 
upperparts. | 
Simosciurus stramineus zarume (Allen). 
Sciurus stramineus zarume ALLEN, Bull. Amer. Mus. Nat. Hist., XX XTII, p. 
597, Sept. 8, 1914. 
Type locality— Zaruma, southwestern Ecuador; altitude 6000 feet. 
Geographic distribution.— Known only from the type locality. 
Description.— “ Like S. stramineus nebouai in the presence of a large white 
nape patch, but widely different in general coloration from either typical 
stramineus or nebouxr. 
“ Upperparts (except the white nape patch) washed with yellowish rufous, 
more heavily and more intensely (approaching tawny) on the posterior half of 
the back and hind limbs, more lightly on the head and anterior half of back, 
the black basal portion of the pelage wholly concealed by the long rufous tip- 
ping of the hairs, which on the lower back occupies the apical half; nose and 
outside of fore limbs grayish; underparts gray, passing into white on the 
throat, upper breast, inside of fore limbs and inguinal region; upper surface of 
fore and hind feet intense black, wrists rufous, especially the inner surface, 
and the rufous on the hind limbs extends slightly beyond ankles; tail rufous 
all around where it joins the body, the rest black heavily washed with white. 
“Total length (collector’s measurements), 540 mm.; head and body, 220; 
tail vertebra, 320; hind foot, 60. Skull, total length—; zygomatic 
breadth, —; interorbital breadth, 19; postorbital breadth, 17; breadth of 
braincase, 23; nasals,—; diastema, 14; maxillary toothrow, 10. The 
nasals and zygomatic arches are unfortunately broken. 
Remarks.— “ Although represented by only a single specimen, the color 
differences are so profound that, taken with the geographical conditions, 
it is hard to believe that they do not denote a strongly marked form of the 
stramaneus group. The rufous tips of the hairs on the lower back are as 
long as the dark basal portion.” — Allen, I. c. 
