1881.] INDIAN SPECIES OF MUS. 539 



in none of the numerous specimens of M. alexandrinus I have ex- 

 amined. 



This very handsome Rat may always be readily recognized by its 

 brightly contrasted colours and its long bicolor tail. It is true that 

 many specimens of Mus fulvescens have a somewhat similarly 

 coloured body ; hut they always have the lower side of the tail of the 

 same tint as the upper. 



I have placed "Mus ociomammis" here rather than under J/./m^- 

 vescens, for the reasons already mentioned under that species. 



The distribution of M. jerdoni presents some most interesting 

 points. In Mr. A. R. Wallace's recent work, ' Island Life,' the 

 author, when treating of the islands of Formosa^ and of Java', states 

 that the fauna of each of these two widely-separated places has a 

 noticeable connexion with that of the Himalayan region. Now this 

 species gives us a most interesting instance of the correctness of 

 Mr. Wallace's views. Its headquarters seem to be in the Sikhim 

 region ; but a very young specimen collected by Baron A. von 

 Hiigel in Java is absolutely the same, it possesses even the minute 

 fifth palate-ridge above mentioned ; its fur is somewhat shorter, 

 and, considering its age, more thickly spinous than is the case in 

 Himalayan specimens ; but these differences are only the natural 

 result of a more tropical climate. With regard to Formosa, 2Iics 

 coxinga, Swinh.^ of which the types are in the British Museum, is 

 so very closely allied to this species that I was at first disposed to 

 consider it identical ; but I now think it just separable on account of 

 its longer hind foot (1*4 against 1"15). We thus have, isolated in 

 these three places, nearly related Rats which seem to be quite un- 

 known in the intermediate districts. Mus {Nesokia) nemorivagus 

 presents us with another instance of this sort of distributiou, being 

 found in Nepal and Formosa ; and if, as is just possible, the true M. 

 setifer, Horsf., from Java, is the same, we have a still better example 

 of the relations of these faunas to one another. 



Mus jerdoni seems to be almost entirely a highland species. 

 Those I have seen have come from Darjiling (7000 ft.), Khasya 

 Hills (4000-5000 ft.), and Wilhs Mt., Java (3000 ft.). Jerdon^ 

 mentions specimens from Kunawar (12,000 ft.); but, from the 

 locality, I am inclined to think that they may have been M. niveiven- 

 ter. Dr. Anderson tells me that these Kunawar specimens are not now 

 in the Calcutta Museum ; so that the question of the western distri- 

 bution of this species cannot be settled at present. 



When Blyth originally described M. jerdoni he stated that the 

 head and body measured 4 inches and the tail 3| inches, proportions 

 wholly at variance with those given above ; but I am informed by 

 Dr. Anderson that the type is only half-grown, and that specimens 

 in the Calcutta Museum, undoubtedly identical, measure just about 

 what those do of which the dimensions are given. Mr. Blyth de- 

 scribed this Rat as a species of the subgenus Leggada, on account 



' Chap, xviii. p. 375. - Chap. svii. p. 358. 



3 P. Z. S. 1864, p. 185 (misprinted coninga, see P. Z. S. 1870, p. 636). 

 ♦ Mamm. lud. p. 209 (1867). 



35* 



