Mammals from Northern Angola. 413 



Dimensions of tlie type (measured in tlic flesh) : — 



Head and body 400 mm. ; tail 469 ; hind foot 78 ; ear 47. 



Skull : greatest length 82 ; basilar length 67 ; zygomatic 

 breadth 38 ; nasals 34 X 11*8 ; interorbital breadth 12 ; brain- 

 case, breadth 26; palate length 40; diastema 25; palatal 

 foramina 8'2; length of upper molar series 12"1. 



Typical locality. Pungo Andongo. 



Type. Old male. B.M. no. 4. 4. 9. 91. Original number 

 39. Collected 9th June, 1903. 



In its large size, unwhitened belly, and dark metacarpals 

 this huge rat differs from any of the forms of the widely 

 spread G. gamhianus, and seems to represent a special 

 Angolan species. The two forms of the group, no doubt 

 synonymous with each other, from Landana described by 

 E,ochebrune * are both far smaller and have their bellies '' albo- 

 cinereis." 



A comparison of the specimens of C. gamhianus in the 

 Museum shows that the typical form occurs from the Gambia 

 down tlirough the forest-region of West Africa to the Congo, 

 and eastwards to Monbuttu. It is chocolate-brown along 

 the dorsal area, paler on the sides, and with a sharply defined 

 white belly. Further south, from the lake-region to Portu- 

 guese South-east Africa, it is replaced by a paler form, which 

 may be called 



Cricetomys gamhianus viator, subsp. n. 



Size and general characters as in Mus gamhianus, but body- 

 colour much paler;, the back " wood-brown," scarcely darker 

 along the spine. Under surface white, not quite so sharply 

 defined as in gamhianus. Tip of muzzle and orbital rings 

 dark brown ; edges of upper lip white j cheeks like flanks. 

 Upper surface of hands white, the brown of the forearm 

 ending on the wrists. Centre of metatarsals dark brown, 

 the toes prominently contrasted white. Tail half blackish, 

 half white, the two colours hardly so strongly contrasted as 

 in G. Ansorgei. 



Dimensions of the type (measured in skin) : — 



Head and body (stretched) 415 mm. ; tail 370 ; hind 

 foot Q^ ; ear 44. 



Skull : greatest length 73 ; basilar length 62 ; zygomatic 

 breadth 35; nasals 31x11 ; interorbital breadth 11*3; pala- 

 tal foramina 8'7 ; length of upper molar series 105. 



* Cricetomys dissiiinlis and Mus iej)hrus, Bull. Soc. Philoin. (7) ix. 

 pp. 86, 87 (1885). 



