Classification of the Otomyinre. 209 



although isolated individuals from elsewhere may be nearly 

 as large. The skull of the type even exceeds in length, 

 though not in bulk, that of the large 0. (Anchotomys) 

 anchietce of Angola. 



Otomys roivleyi, sp. n. 



Like 0. irroratus superficially, but apparently really a 

 representative in Portuguese S.E. Africa of the 7-laminated 

 forms of the Zambesi and northwards. 



General appearance and colour quite as in 0. irroratus 

 cupreus, but the fur shorter and coarser. Ears and tail not 

 very heavily furred. 



Skull of medium size, about equalling that of 0. irroratus. 

 Nasals differing from those of other S. African forms by 

 their even expansion anteriorly, and the absence of a definite 

 angle at the point where the narrow part passes into the 

 broad — this character quite uniform in the one adult and 

 four young specimens before me. All the other S. African 

 forms have a marked angle at the point referred to. 



Teeth. Third upper molar with seven laminae in every 

 specimen, this number being that characteristic of the 

 Zambesi and more northward Otomys, only rarely and 

 exceptionally occurring in 0. irroratus. 



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



Head and body 167 mm. ; tail 92 ; hind foot 27 ; ear 20. 



Skull : greatest length 40 ; condylo-incisive length 37*7 ; 

 zygomatic breadth 19"7; nasals J8x7*4; upper molar 

 series 9*1. 



Had. Coguno, Inhambane, Portuguese S.E. Africa. 



Type. Adult female. B.M. no. 6.11.8.77. Original 

 number 1585. Collected 31st July, 1906, by C. H. B. 

 Grant. Presented by Mr. C. D. Rudd. 



Accidentally overlooking the fact that one of the series 

 was fully adult, Mr. Wroughton and I provisionally referred 

 this animal in 1906 to 0. irroratus cupreus, but I now con- 

 sider that its constant possession of seven laminae in m 1 

 indicates that it is a southern representative in the low hot 

 coast-lands of the more northern forms characterised by that 

 number of laminae, while only six is usual in irroratus. The 

 absence of an angular corner halfway along the lateral nasal 

 sutures is also a character which affines it to some of the 

 more northern forms and distinguishes it from O. irroratus. 



It is named in honour of Mr. P. R. Rowley, Curator of 

 the Royal Albert Memorial Museum at Exeter, lo whom 

 both officially and privately the Mammal Department of the 

 National Museum is greatly indebted for assistance. 



