SCIENTIFIC RESULTS FROM THE MAMMAL SURVEY. 421 



Dimensions of the type, measured in the flesh : — Head and body 

 99mni ; tail 78-5; hindfoot 17; ear 13. Skull, greatest length 

 24-2; condjdo-incisive length 28-5 ; zygomatic breadth 12; nasuls 

 9; interorbital breadth 3-7; palatilar length 12-2; palatal 

 foramina 5'5 ; upper molar series 3-9. 



Hah. : — Mt. Popa, Dry Zone of Burma. 



Ti/pe -.—Okl male. B. M. No. 14, 7, 19, 200. Original number 

 3917. Collected 29th September 1913 by G. 0. Shortridge. Pre- 

 sented by the Bombay Natural History Society. Seven specimens. 



Mus gentihilus, sp. n. 



A small species of restricted Mus, about the size of M. sjncilerpis, 

 but with the coinparatively long tail of Mus muscnlus and 

 gentilis. 



Size small, form slender. General colour as in 31. ijentilis, the 

 upper sxirface sandy fawn, the posterior back warmer, under- 

 surface white, the hairs white to the roots in the type, but slaty at 

 base in another specimen, and in yet another, they are slaty basally 

 and washed terminally with dull biiff}', as in the house haunting 

 Mus maisculus. Ears, of moderate size. Hands and feet white. 

 Tail, of about the length of the head and body, varying from a little 

 shorter to a little longer. 



Skull, of about the size and shape of M. sjncileijus or rather 

 smaller ; markedly smaller than that of (jevtilis. 



Dimensions of the type, measured in the flesh : — Head and body, 

 65 mm; tail, 06; hindfoot, 15-5; ear, 12. 



Skull: — Greatest length, 20*3; condylo-incisive length, 19; 

 zj'gomatic breadth, lO-G; nasals, 8-6; interorbital breadth, 4; 

 palatal foramina, 5; upper molar series, 3*3. 



Rah. — Aden. Type from Laliej, other s]3ecimens from Sheikh 

 Othman. 



%)e.— Adult male. B. ]\1. No,. 99, 11, G, 71. Original number 

 37. Collected 23rd August 1899 by W. Dodson. Five specimens. 



This little mouse is the Mus hadrianus of the first and the No. 

 23 of the second of my papers on Aden Mammals (P. Z. S., 1895 

 p. 554 and 1900, p. 103). Its small size suggests a Leggada, but 

 it is clearly a true Mas, and seems most related to 31. gentilis, from 

 which it differs by its markedly smaller size. On the other hand, 

 judging by the length of the tooth-row, it is larger than A/, ahhotti, 

 Waterh., of Trebizond, as yet only known to us by the immature 

 type specimen. From the members of the si3icilegu,s group it is 

 distinguished b}^ its longer tail. 



