156 Mr. G. Dollman oti the 



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



Head and bodj 1G6 mm. ; tail (broken) * ; hind foot 26*5 ; 

 ear 21. 



Skull : greatest length 40 ; basilar length 31*9 ; condylo- 

 incisive length 36"7 ; zygomatic breadth 20*7 ; interorbital 

 constriction 3'8 ; length of nasals 18'2; greatest breadth 

 across expanded part of nasals 7*3 ; depth fiom highest 

 point of orbit to alveolar border at front of ni^ ]3"6 ; length 

 of palatal foramina 7*5; postpalatal length 14'2 ; length of 

 upper molar series from anterior alveolar border to back of 

 last molar 9'5 ; length from anterior base of enamel on m} to 

 back of m^ 8'8 ; greatest widtii of m^ 2*5. 



Ilab. Mt. Kinangop, Aberdare Range, British East Africa. 

 Altitude 12,000 feet. 



T2/pe. Old male. B.M. no. 10. 5. 3. 41. Original num- 

 ber 713. Collected by Mr. Robin Kemp on February 27th, 

 1910, and presented to the British Museum by Mr. C D. 

 Rudd. 



* The smaller size of this Aberdare Otomys immediately 

 se))arate3 it from the large i\lolo form, while the darker 

 and richer colour of the fur serve to distinguish it from 

 malleus. 



Mr. Kemp collected four specimens of this Otomys from 

 localities on the Aberdare Mountains ranging between 10,000 

 and 12j000 feet in altitude ; all four specimens are exactly 

 similar in general colour. This must be regarded as a 

 mountain race of thomasi. 



Group 2. 

 m'^ with only 6 laminse. 



(6) Otomys Orestes, Thos. 

 Otomys irroratus orestes, Thos. P. Z. S. 1900, p. 17o. 



The skull in this species exhibits the same striking arched 

 appearance as is seen in thomasi and the allied races described 

 above. The last upper molar, however^ only possesses 6 

 larainse. 



In general colour orestes is lather similar to the Aberdare 

 race of thomasi described above as T. squalus ; the dorsal 

 surface is rather richer and browner, but otherwise there is 

 very little ditference. 



Dimensions of the type : — 



Head and body 175 mm.; tail 62 ; hind foot 27; ear 20*5. 



* In another specimen from the type-locality the tail is given as 

 88 mm. in length, 



