ALLEN: NEW AFRICAN RODENTS. 447 



scantily clothed with minute pale hairs and obscurely edged with 

 blackish. Proximal third of the tail like the back, scarcely paler 

 below; terminal half or two thirds above and below clad with dark 

 hairs, nearly seal-brown, which lengthen progressively toward the 

 tip, especially above, forming a terminal tuft, whose longest hairs 

 measure about 15 mm. Ventral surfaces of body and limbs pure 

 white to the roots of the hairs except about the ankles where is a 

 ring of hairs seal-brown to their bases. 



Skull. — The posterior palatal foramina extend, as in other mem- 

 bers of this genus, from the level of the front of the first molar to the 

 middle of the second. The upper incisors have a distinct groove 

 slightly external to the center. The nasals are exceeded by the 

 posterior prolongations of the premaxillaries and are squarely truncate 

 proximally instead of tapering to a median point. 



Measurements. — The type measured in the flesh: head and body 

 122 mm.; tail, 165; hind foot (c. u.), 33; ear from meatus, 18. The 

 skull measures: greatest length, 36.2; basilar length, 26.5; zygomatic 

 breadth, 18; nasals, 14; interorbital constriction, 7; mastoid breadth, 

 16.5; diastema, 9; upper molar series, 5; audital bullae, 10 by 5.5. 



Remarks. — This is a pale form from the arid plateau to the north 

 and west of Mt. Kenia, bordering the Guaso Nyiro. It seems related 

 to the rufous T. osgoodi of the coast or perhaps to T. tenebricus but 

 differs in size, color, and the character of the black markings of the 

 head from all of these. It seems to represent a distinct species from 

 T. nubilus illustris, also found in the Guaso Nyiro region, which in 

 addition to smaller size, differs notably in having practically no 

 black cheek-patch. 



