417 



SCIENTIFIC RESULTS FROM THE MAMMAL SURVEY. 



No. XIX. 



A Synopsis of the Groups of true Mice found within 

 THE Indian Empire. 



By Oldfield Thomas. 



At the request of Mr. Wroughton, with a view to the prepara- 

 tion of his " Summary," I have made an attempt to find out the 

 natural relationships to each other of the many forms of " Mus " 

 that have been described from the Indian Empire, and now venture 

 to submit, with some diffidence, the following synopsis of these 

 most difficult animals. 



As will be seen, it is very far from being a complete working out 

 of the species, but at least it sorts them into their natural groups, 

 and so makes a step towards their further elucidation. 



The characters given in the synopsis are of necessity not such as 

 can be used by sportsmen in the field, being mainly based on the 

 skulls, of which some technical knowledge is needed — but this is 

 a fault which is inherent in all such work. 



8yno2ms. 



A. Muzzle short — distance from gnathion 



to front bottom corner of zj^goma- 

 tic plate not, or barely, exceeding- 

 breadth across molars. (True 

 House Mice.) 

 a\ Tail about as long as head and body. 

 a^. Colour some tone of grey or 



brown ... ... •••(!) nmsculus group.* 



If. Colour more or less sandy, with 



v/hite belly ... •••(2) hactrianus group. f 



h\ Tail much shorter than head and 



body — colour sandy ... •••(3) iJacliycercus.\ 



B. Muzzle normal — the distance above. 



defined decidedly greater than 

 breadth across the molars. (Field- 

 Mice.) 



* Includes, of Indian species, dubhis, ho^nounis and iir bonus, {'iS4a),a'qnicaudalis 

 (1851), manei (1852), tytleri HSi^'J), kakhycnsis and viculorwu (187 H i. 



t Includes gerhillinus and tlieobaldi (1853). Althoug'h provisionally put as a 

 '■ group" there is little doubt that bactrianus will prore to grade into imiscuhis 

 throug-h such forms as Mus musculus gentilis of N. Africa, Arabia, &c. 



+ Not strictly Indian having- been described from Yarkand . Probably it is 

 synonymous v.'ith M. loagneri. 



