160 



I\Ir. G. Dollinan on the 



The cliii'T cliaracters tl:at si'))aratc this Nyiro Olomya 

 from the El^on race are its smaller size, smaller teeth, and 

 very imich j)aler-colouretl pelage. 



Croup 2. 



Nasals not exceptionally broad (not more than S mm. in width), but 

 showing no angular transition between the broad and narrow 

 portions, pattern rather trumpet-shaped. 



(11) Otomys tropicalis nuhilus, subsp. n. 



A very dark raee, related to elgonis and tropicalis. 



Size and general proportions as in eJgonis. 



Colour of dorsal surfaee dark se))ia-brown speckled with 

 buffj the general effect is very nearly as dark as in denti and 

 the allied spi'cies 0. kempi ; both elgonis and trojncalis are 

 considerably lighter in colour. Flanks rather more thickly 

 speckled with buff. Backs of hands and feet as in elgonis, 

 ventral surface of body slate-black Sj)eckled with pale buff, 

 the whole a shade darker than in the Elgon form. 



Skull about equal in size to that of elgonis, but dis- 

 tinguished by the shape of the nasals which do not show any 

 sudden subterminal constriction, the expanded anterior por- 

 tion narrowing gradually without the angular compression 

 so conspicuous in elgonis and troiyicalis. The general appear- 

 ance of the nasals is rather that of a very narrow example of 

 the angoniensis pattern. The inner groove of the lower 

 incisors in this furm is fairly well developed, more so than in 

 tropicalis, where the inner groove is no more than a very 

 shallow depression. In elgonis there would seem to be a 

 certain amount of variation as regards the development of 

 this inner groove, in the type-specimen it is fairly well 

 formed, while in others from the type-locality this groove is 

 very indistinct. The molars are quite like those of tropicalis 

 and elgonis, m^ having seven laminfe. 



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



Head and body 170 mm.; tail 80; hind foot 28-5; 

 ear 20. 



Skull : greatest length 41'0 ; basilar length 33'7 ; con- 

 dylo-incisive leiiglh 38*5; zygomatic breadth 19*.5; inter- 

 orbital constriction 4'7; breadth of brain-case 16; greatest 

 length of nasals 17; greatest anterior width of nasals 7*7; 

 median width 4'1 ; palatilar length 19; lengtli of palatal 

 foramina 8 ; length of upper molar series from anterior 

 alveolar border to back of last molar 10 ; width of m^ 2*7. 



Hah. Jombeni (Igembi) Range, N.E. of Mt. Kenya. 

 Altitude 6000 feet. 



