NILS GYLDENSTOLPE, MALAYAN BIRDS AND MAMMALS. 29 



skull is also much more robust than in the Bornean animai, 

 in which the nasals are more tapering off posteriorly. How- 

 ever, all Oriental råts are very variable and vvitliout a large 

 material for comparison it is impossible to draw any con- 

 clusions about the relationship of the different species. 

 Skull measurements: 



R. asper i R. ivhile- R. ivhite- 



, ef 1 headi ö" headi $ 



' i ^ 



Greatest length 33,0 mm 32,3 mm 33,8 mm 



Condylus to gnathion 32,1 » 29,5 » 30,0 » 



Basicranial length 29,5 » 27,1 » 27,0 > 



Zygomatic width 16,5 > — | 14,1 



Width of brain caso 13,6 » 13,5 » [ 13,1 » 



Least interorbital width 4,8 » 5,5 » j 5,1 » 



Length of nasals mesially 11,8 >• 11,3 » 12,0 » 



Breadth > » anteriorly .... 3,0 » 3,0 » 2,7 » 



I » » >; posteriorly . . . . ' 1,7 >' 1,5 » : 1,2 » 



Diastema i 8,5 ;> 7,9 « I 8,1 ' 



Lenjrth of foramina incisiva .... 5,8 » 5,1 » \ 4,5 » 



Breadth of combined foramina 

 Length of upper toothrovv . . 



1,4 » 2,1 » 2,1 



G,5 ;' 5,2 » , 4,9 



10. Rattiis rattiis jaloreiisis BoNH. — 1 ? ^'A 1915. Nose 

 to vent = 153; Tail = 150; Hindfoot = 32 mm. 



Both this and the next species are rather common in the 

 Malay Peninsula. R. rattus jalorensis seems, however, to be 

 a jungle species and not a house rat as It. r. griseiventer 



BONH. 



The single specimen obtained seems to be quite typical 

 and is easily distinguished by its dark upper surface and its 

 short tail. 



Skull measurements: Greatest length = 37, i; length 

 from condylus to gnathion -= 35,3; basicranial length = 33, i; 

 greatest breadth of brain case = 14,4; least interorbital width 

 =-4,8; length of nasals mesially = 12,8; breadth of combined 

 nasals at anterior extremity = 3,5; breadth of combined nasals 

 at posterior extremity = 1,6 : diastema = 10, o; length of fora- 

 mina incisiva = 6,8 ; length of upper toothrow = 7,i mm. 



11. Kattus rattus ii:risciventer Bonh. — 1 ? ^Vil915. 



