528 Mr. G. Dolhnan on 



than in the allied species. Zygoma stout and heavy. Palatal 

 foramina very long. Auditory bullae large and slightly in- 

 flated. Molar teeth exceptionally large, the tooth-row 

 much longer and broader than in T. ibeanus or any of the 

 surdaster group. 



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



Head and body 132 mm. ; tail 201 ; hind foot 26-5 ; 

 ear 19. 



Skull : greatest length 35-5 ; basal length 29-5 ; basilar 

 length 275 ; condylo-basilar length 29'8; condylo-incisive 

 length 31 8 ; zygomatic breadth 1G"9 ; iuterorbital breadth 5 ; 

 breadth of brain-case (across squamosal region) 14 ; greatest 

 length of nasals 12*7 ; palatilar length 14*5 ; width of palate 

 (inside m^) 3 ; width across palate (outside m^) 6 ; length 

 of palatal foramina 7'9 ; post-palatal length 13*3 ; length of 

 upper molar series 5'5. 



Hab. Solai, Mt. Kenia. Altitude 9000 feet. 



7y/5e. Adult male. Original number 1712. Collected on 

 December 28th, 1910. 



This large species is distinguished at once from all the 

 allied forms by the far greater size of the skull. A 

 further specimen referable to the same species was collected 

 by Mr. J. L. Clark at Kasituka, west of Mt. Kenya. 



Tliamnomys surdaster bisignis, subsp. n. 



S. 1517; ?. 1467. Rumruti, Laikipia Plateau. 



(J. 415, 451; ?. 427, 433, 446. South face of 

 Mt. Elgon. 



Rather smaller in size than T. ibeanus, Osg., but much 

 redder in colour and allied to T. surdaster polionops, Osg. 



General colour of back much as in T. surdaster, but darker 

 and less richly coloured anteriorly ; the entire dorsal surface 

 washed with tawny buff, richer on the posterior portion of 

 the body. General colour of hind-quarters reddish buff 

 (brownish terracotta no. 2, ' Repertoire de Couleurs ') . Flanks 

 pale olive-grey, strongly tinted with pinkish buff, sharply 

 marked off from the white underparts by a pale bufi-coloured 

 line, formed by the pinkish-buff tips of the hairs of the flanks 

 overlapping the white hairs of the belly. Hairs of back and 

 flanks all with dark slate-grey bases. Face and head much 

 as in T. ibeanus, but more buffy. Backs of hands and feet 

 white, washed with buff. Entire underparts white ; hairs 

 wholly white. Tail long and hairy, about as in T. ibeanus. 



Skull much as in T. surdaster, rather larger in size, 

 though not so large as in 7, ibeanus. 





