202 Bulletin American Museum of Natural History. [Vol. XXXIV, 
hairs of the tail were worn, the tail of rufoniger would present this appear- 
ance. Alston appears to have compared the type of chrysuros with the type 
of rufoniger (both then in the Paris Museum) and says of them (Proce. Zool. 
Soc. London, 1878, p. 669): “The type of S. rufoniger has the middle of the 
back nearly black; while that of M.[= S.] chrysurus appears to be a variety, 
merely differing in the tail being more rufous.” My present material sup- 
ports Alston’s opinion. 
Leptosciurus pucheranii medellinensis (Gray). 
Macroxus medellinensis Gray, Ann. and Mag. Nat. Hist. (4), X, p. 408, Nov. 
1872. 
Geographic distribution. Known only from the vicinity of the type 
locality. : 
Description.— Similar above to L. p. pucheranw; ventral surface clear 
“white superficially, the basal plumbeous portion of the pelage along the 
sides of the abdomen showing through. A Valdivia specimen has the ven- 
tral surface heavily washed with buff. 
Total length (2 specimens, Valdivia, collector’s measurements), 310, 310 
mm.; head and body, 160, 170; tail vertebree, 150, 140; hind foot (without 
claws), 39, 40; ear, 19,18. No skull available at this writing. 
Specumens examined, 3.— Colombia: Medellin, 1, topotype; Valdivia 
(near Medellin), 2 (all Br. Mus.). [See Addenda, p. 307.] 
Remarks.— L. pucheranti medellinensis was originally described from 5 
specimens from Medellin, two of which became the property of the British 
Museum, to which specimens from Valdivia have been since added. These 
I saw in April, 1913, but at this writing have only my notes to rely upon. 
Gray in describing the species compared it with his Macroxus tephrogaster 
(= Sciurus deppei Peters), from Guatemala and Mexico, stating that it 
was “not above half the size of the more southern [northern] specimens,”’ 
and that he was inclined to regard them “as a variety or species, under the 
name of Macroxus medellinensis.’’ He comments on the variability of the 
black dorsal band, which in one of the two specimens used in his description 
extended from the base of the neck to the tail, while the other had a very 
indistinct dorsal streak, with a squarish black spot on the middle of the back; 
in the former the white on the ventral surface was confined to “the middle 
of the throat, chest, and belly, the sides being grayish,” while in the other the 
ventral surface was much whiter. A Valdivia specimen has the belly deep 
buff, showing that the usual wide range of individual variation in the color of 
the underparts obtains in this as in the other forms of the pucheranii group. 
1 Cf. Nelson, Proc. Washington Acad. Sci., I, p. 103, May 9, 1899. 
