412 JOURNAL, BOMBAY NATURAL HIST. SOCIETY, Vol. XXIV. 



Eprmys mackenziei fece, stibsp. n. 



Size of body slightly less than in trne mackenziei, but tail and 

 feet, averaging longer. Colour apparently about as in true mackenziei , 

 except that there is rather more brown on the feet. Tail with only 

 its extreme tip (8 mm, in the type) white, instead of its terminal 

 two-fifths. 



Skull essentially as in mackenziei, but zygomatic plate rather 

 narrower, palatal foramina less open, bullse rather smaller. 



Dimensions of the type, measured on the spirit specimen : — Head 

 and bodj^ 215 mm.; tail 261 ; hindfoot 51 ; ear 26. Skull, greatest 

 length 50*5 ; condylo-incisive length 49 ; zygomatic breadth 25 ; 

 nasals 20; interorbital breadth 7'8; breadth of braincase 19; pala- 

 tilar length 24' 5 ; palatal foramina 9; upper molar series 9. 



Hah. — Thagata, Muleyit Range, Tenasserim. 



%je— Adult female. B.M. No. 88.12.1.47. Collected by 

 L. Fea and presented to the British Museum by the Marqtiis CI. Doria. 



Another specimen, now in the Museo Civico, Genoa, had a tail 

 285 mm. in length (measiired from anus) and hindfoot 52. 



4. — The Rats of the Epimys bebdmorei group. 



Mr. Mackenzie obtained in the Chin Hills a fine series of the 

 grey rat, coloured somewhat as in ii". hotversi and mackenziei, but far 

 smaller, w^hich I recorded as " Mus herdmorei, Blyth " on Hume's 

 specimens from Manipur. 



In working these out I have had before me practically all the 

 known specimens pertinent to the question, namely, (1) by the 

 kindness of the authoiities at Calcutta, the typical skull from 

 Mergui, collected by Berdmore and described by Blyth, (2) Hume's 

 specimens from Manipur, (3) one of the two specimens in the Fea 

 collection, recorded by me as Mus herdmorei in 1892, now, by Dr. 

 Gestro's help, transferred in exchange to the British Museum, (4) 

 the type of Epimi/s herdmorei magnits, Kloss, recently described from 

 S.-E. Siam, and (5) Mr. Mackenzie's series from the Chin Hills. 



Study of this valuable material shows that there are in the group 

 no less than four definable forms, namely, a distinct species in the 

 North (to which 2 and 5 of the above list belong) and three sub- 

 species of JE. herdmorei in the South (1, 3 and 4). 



These four forms are all very similar externally, though there is 

 some difference in the amount *of white on the tail. All have 

 3-2=10 mamm^, and the same general colour. 



The skulls are all of the same characteristic shape (see Kloss's 

 figure, P.Z.S., 1916,) with whitish or pale yellow incisors, 

 these being much thrown forward, their angular relation to 

 the molar series, measured as described above, about 70°-75° in the 

 northern form, 80"-85° in the southern ones. 



