KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 60- NIO 6. 41 



37. Rattus rapit Bonhote. 



Ann. & Mag. Nat. Hist., 7 ser., vol. XI, 1903, p. 123. 



No. ,20. J 1 Camp 5, Eastern Borneo "/i 1914. Head and body: 163 mm. Tail: 183 mm. Hindfoot: 

 34 mm. Ear: 21 mm. 



This single specimen is fairly similar to R. rapit Bonh., the type of which 

 was obtained on Mount Kina Balu, Northwestern Borneo. It differs, however, in 

 several particulars as will be seen by the description given below. 



General colour above ochraceous-tawny intermixed with some black hairs, most 

 predominant along the centre of the lower back. Under parts of the body påle 

 cream-coloured and sharply marked off from the sides of the body. On the middle 

 of the belly there is an elongate brownish area similar to that recorded by Thomas in 

 R. rajah, from which the present species differs by its smaller size. Tn the type 

 specimen of R. rapit the whitish colour of the underparts does not extend to 

 the feet, which are said to be dark brown. In the present specimen, however, the 

 whitish colour extends as a line down to the heel, and is conterminous with the 

 creamy white feet. Outer side of the före legs whitish tinged with påle ochraceous. 

 Tail bicolor, blackish brown above, whitish below, which colour is sharply marked 

 off from the dark colour of the upper parts of the tail. The long vibrissse and the 

 eye-bristles are blackish, the former lighter at the tips. 



Skull measurements (the measurements in pharentesis are those of the type 

 specimen of R. rapit)'. Greatest length of skull: 39,5; length from condylus to 

 gnathion: 36,9; basicranial length of skull: 34,3; zygomatic width: 16.8 ( 1 8,o); greatest 

 width of braincase: 14.2 (16. o); length of nasals mesially: 15, o (15, o); breadth of 

 combined nasals at anterior extremity: 3,5; breadth of combined nasals at posterior 

 extremity: 2,i; diastema: 10,5 (ll,o); length of foramina incisiva: 5,5 (6,5); least 

 interorbital breadth: 5,8 (6,5); length of upper molar series (alveoli): 5,8 (6, o); length 

 of lower molar series: 6,1 mm. 



Remarks: The bullse are very small and rather flattened. The muzzle is rather 

 long and narrow, and the nasals end some distance behind the nasal branches of 

 the premaxillare. The supraorbital ridges are well-marked and extend well back- 

 wards. Between the ends of the nasals and the roots of the zygomata there is a 

 slight swelling. 



This species was not recorded by Lyon in his account of the Mammals ob- 

 tained by Doktor W. L. Abbott from various parts of Borneo (Proc. U. S. Nat. 

 Mus., vol. 40, 1911). 



K. Sv. Vet. Akad. Handl. Band 60. N:o fi. 



