74 JOURNAL, BOMBAY NATURAL HIST. SOCIETY, Voi, 2CKF1. 



The skull and teeth do not differ from those of R. r. Ustoe in 

 Miy important respect. 



3. Battus rattus arboreus, Buchanan-Hamilton. 



1851. Mtts arboreus, Buchanan Hamilton in Horsfield, Gat. 

 Mainm. Mus. E. India Co., London, 1851, p. 161 ; described from 

 " Bengal," the type being unknown. 



1865. Mus Tufescens, Blyth, Cat. Mamm. Mus. As. 8oc., Calcutta, 

 p. 115 (in part); Jerdon (in part). 



1881. Mus alexandrinus, a. typical var., Thomas, P. Z. 8. 1881, 

 p. 532 (in part). 



In a portion of his MS. (first published hj Horsfield. loc. eit. 

 supra). Dr. Buchanan Hamilton described a rat said to live in the 

 cocoanut trees and bambocs of Bengal. The upper parts are said 

 to be " dark iron-grey, consisti.ig of black and tawny hairs, of 

 which the former are the longest and most numerous. The lower 

 parts and legs are white ; the naked parts of the nose and toes are 

 pale flesh colour." The head and body lengths of a full-grown 

 male and female are given as 7" and 8^", their tails as 7^" 

 and 9" respectively. If we suppose these measurements to have 

 been taken on stretched skins, then this description, eo far as it 

 goes, will apply to many of the specimens obtained by the Mammal 

 Survey in Bihar and Orissa. The Survey material indicates that 

 the race inhabiting this part of Bengal is deserving of subspecific 

 recognition, and I therefore propose to revive the name arborew 

 and to use it for the subspecies in question. Mr. Thomas (P. Z. S., 

 1881, p. bVZ) has pointed out long ago that aiboreus is based 

 upon the description (and a drawiug) cited above and not upon 

 the specimen mentioned by Horsfield which is a Brown Rat 

 (B. norvegicus). Mr. Wroughton (/. Bombay Nat. Hist. Sac, Vol. 

 XXI, p. 1190) has already stated that should a name be required 

 for the " white bellied variety of rufescens' then " arboreus, 

 Buchaman Hamilton, is available and most apposite," 



Distribution: — Probably throughout the greater part of Bengal to 

 the south aT?d west of the Ganaes. 



Material examined : — In addition to some old material in the 

 British Museum I have had at my disposal the following 72 speci- 

 mens collected for the Mammal Survey by Mr. C. A. Crump: — 

 17 (4 J 13$) from Daltonganj ; L (^) from Palamau ; 3 

 ( J ) from Barkagaon ; 1 ( 5 ) from Jagodih ; 4(2 j , 2 5 ) from 

 Lohra ; 19 (7 c?,l2 $) from Gajhundi; 5 (3 c? , 2 $ ) from 

 Singar ; 2 ( (j and $) from Nimiaghat ; 15(8 c? . 7 5 ) from 

 Pareshnath Hill ; 1 ( $ ) from Sangajata, Chaibassa; and 4 (2 j , 2 

 2 ) from Luia, Chaibassa. Specimens from this collection are regis- 

 tered in the British Museum under the serial number 15- 4* 3.— 



