488 Mr. 0. Thomas on 



■that the liairs of the terminal half of the tail, broadly ringed 

 subterminally with black in igniveniris, are wholly red 

 beyond their basal ^ inch, which is dark brown. A very 

 few hairs at the extreme tip of the tail are, however, indis- 

 tinctly black-ringed. Size rather less than in the typical 

 form, and ears apparently rather shorter. 



Dimensions of the type (measured in skin) : — 



Head and body 285 millim. ; tail 2S5; hind foot (s. u.) 

 (wet) 59 ; ear (wet) 31. 



Sknll : greatest length 65 ; basilar length 50 ; zygomatic 

 breadth 36*5; diastema 17*8 ; palatal foramina 4*5 ; length 

 of upper tooth series lO'l. 



Hah. Sabafia Grande, near Bogota. 



Type. Male. B.M. no. 98. 7. 3. 6. Collected 15th May, 

 1896, by Mr. G. D. Child, and presented by Oldfield 

 Thomas. 



This is the squirrel which, in 1900 *, I assigned to the true 

 S. igniventi-is, but further study and material induce me to 

 think it represents a definable local form. 



Sciurus castus^ sp. n. 



Allied to S. pyrrhonotus, Wagn., but with white belly. 

 General colour above grizzled tawny ochraceous, darker and 

 greyer on the head. Ears, cheeks, and upper surface of 

 fore limbs richer tawny. Outer side of hips and upper 

 surface of hind feet deep ferruginous red. Chin tawny, 

 ctheiwise the whole of the under surface and the inner sides 

 of the limbs pure sharply defined white. Basal two inches 

 of tail like back, the hairs of the remainder blackish brown, 

 broadly washed terminally with bright rufous. 



Dimensions of the type (measured in the flesh) : — 



Head and body 244 millim.; tail 250; hind foot (s. u ) 

 60; ear 30. 



Skull : greatest length 65 ; basilar length 48*5 ; length of 

 upper molar series (true molars only) 8. 



Hah. of type. Chimate, Bolivia; 68° W., 15° S., on the 

 Upper Rio Beni. Alt 700 m. 



Type. Female. B.M. no. 1. 2. 1. 7. Original number 

 1229. Collected 19th September, 1900, by Mr. P. O. Simons. 



A second specimen collected by Signor L. Balzan, also in 

 the province of Yungas, is rather redder on the back, but 

 has the same pure white belly. 



This fine squirrel is evidently the Beni representative of 

 S. pyrrhonotus, "Wagn. (type locality, Borba, on the Lower 

 Madeira), from Avhich it differs by its pure white, instead of 

 " weisslichgelb oder ockergelb," under surface. 

 * Ann. & Map-. Nat. Hist. (7) vi. p. 137. 



