Sivamp-Ra's of East Africa. 157 



Skull : greatest lengtli 38*6 ; basilar lenolh 31 ; zygo- 

 matic breadth 20; breadth of brain-case 16-5; lengtli of 

 nasals 17; greatest width across expanded portion 7*1; 

 depth from liighest point of orbit to alveolar border at front 

 of m^ 13*2 ; palatilar length 17 ; length of upper molar series 

 from front alveolar border to back of tn^ 9*6. 



Hah. Teliki Valley, west slope of Mt. Kenya. Altitude 

 13.000 feet. 



Tt,pe. Old male. B.M. no. 0. 2. 1. 21. 



(7) Otomys orestes dollmani. Hell. 



Otomys orestes clollmani, Heller, Smith. Misc. Coll. vol. lix. no. 16, 

 p. 5 (1912). 



Agrees with orestes in that m^ possesses only 6 laniinoe, 

 but skull less arched and narrower, with smaller bullse and 

 teeth, and pelage considerably darker in colour. 



Tlie specimens of this Gargues (Urguess) 0/t)????/5 collected 

 by Mr. Blayney Peroival are, unfortunatel}', too young to be 

 of any systematic use. 



In colour this race would appear to be similar to tropicalis, 

 i. e., a rich tawny olive above and slate-grey sutFused with 

 brownish buff below. 



The dimensions given by Heller are : — ■ 



Head and body 150 mm. ; tail 88 ; hind foot 25 ; ear 21. 



Skull: greatest length 37'4; basilar length 29*2; zygo- 

 matic breadth IS'l ; interorbital constriction 4'9 ; nasals 

 17*2x7; postpalatal length 12; length of upper molar 

 series (alveolar) 8*1. 



Mr. Heller, when describing this form, mentioned that he 

 had five specimens from the type-locality all agreeing in 

 laminal formulje, i. e., tn^ with only 6 lamina?. 



Bah. Mt. Gargues (Mt. Urguess). Altitude 7000 ^Qtt. 



Section II. 



Skulls without any marked elevation of the interorbital region, the 

 general line of the brain-case nearlj' horizontal anteriorlj\ vv'' with 

 7 laniiniB. 



Group 1. 



Nasals not exceptionally broad anteriorly (not more than 8 mm. in 

 width) ; transition from broad to narrow region marked by a distinct 

 angle, resulting effect rather spoon-shaped. 



(8) Otomys tfopicalisj Thos. 



Otomys irroratus tropicalis, Thos. Ann. & Mag. Nat. Hist. (7) vol. x. 

 p. 314 (1902). 



A dark brown ish-buflf-colouied species, distinguished from 



