On new Forms of Sciurus, Oxymycterus, &c. 487 



Colour. Upper parts very dark greyish fulvous, becoming 

 more fulvous posteriorly. Dorsal area heavily lined witli 

 black, so as to be nearly black in old specimens, and quite 

 black in young ones, in which it is sharply detined from the 

 lighter lateral colour. Sides dull fulvous brown, rather 

 darker than in allied forms. Underparts dull grey (grey 

 no. 7), darker and less sharply defined than in melanotis. 

 Ears black, their white edge more conspicuous than iu 

 melanotis. Feet dull whitish above, the dusky of the ankles 

 trespassing a little on the metatarsals. Tail heavily haired, 

 black above, white on sides and below. 



Skull practically as in melanotis, but the muzzle and 

 frontal region inappreciably narrower. 



Measurements of the type : — 



Total length 169 millim.; head and body 91; tail 75; 

 hind foot, s. u. 20, c. u. 21 ; ear 18. 



Skull: greatest length 26"5 ; basilar length 20; nasals 

 11x3; interorbital breadth o-y ; palate length 10*9; palatal 

 foramina 5*8x2; length of upper molar series 3'7. 



Hab. Santa Barbara camp, southern slope of Mt. Orizaba, 

 at 12,500 feet. 



Type. Old male. B.M. no. 3. 3. 4. 23. Collected 21st 

 July, 1902. _ 



Four specimens, two old and two immature. 



This animal may be regarded as a saturate mountain ally 

 of the species described as P. melanotis from Las Vigas by 

 Allen and Chapman *, with which it may hereafter prove to 

 intergrade. The darker colour, and especially the heavy 

 blackening of the back, is equally conspicuous in the old and 

 young specimens. The type is quite strongly fulvous on the 

 rump, but this peculiarity is not observable in the other 

 examples. 



LXX. — Neio Forms of Sciurus, Oxymycterus, Kannaba- 

 teomys, Proechimys, Dasyprocta, and Caluromys from 

 South America. By Oldfield Thomas. 



Sciurus igniventris tcediferj subsp. n. 



Coloured in all respects like the typical S. igniventris of 

 the iiio Negro, as described by Wagner |, with the exception 



* Bull. Am. Mus. ix. p. 2J3 (1897). The British Museum possesses 

 an adult paratype of this animal. 



t Abb. Ak. Miinch. v. p. 276 (1850), 



