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ON SOME INDIAN FORMS OF THE GENUS 



MICROMYS. 



BY 



R. C. Wroughton. 



Though the name Micromys was proposed so long ago as 1841, it 

 was not generally accepted until quite recently. In 1905, Mr. 

 Thomas (A.M.N.H., May 1905, p. 492) in describing a Japanese 

 form adopted the name for the group of Field Mice, of which the 

 European representatives are minutus, sylvaticus'*, agrarius and mys- 

 tacinus. He (loc.cit.) recapitulates the chief characteristics of the 

 Genus as follows : — " the posterior lamina of the first and second 

 " upper molars have each an additional internal cusp beyond the 

 " number present in Mus ; so that, counting along the inner side of 

 " the tooth-row, there are three cusps on the first molar and three on 

 " the second, while in Mus the posterior lamina is not continued in- 

 " wards beyond the centre, and there are therefore only two inner 

 " cusps on each of the two teeth." 



Distinct local forms of Micromys sylvaticus occur at intervals over 

 the whole area between its typical home in Europe and Ispahan the 

 type locality of Mus arianus Blanford, and there can be scarcely any 

 doubt that that animal should rank as a subspecies of M. sylvaticus 

 and not as a distinct species. I propose to treat the Indian forms, 

 with which these notes are concerned, also as subspecies of M. 

 sylvaticus. The mammary formula as in " Mus arianus" and typical 

 M. sylvaticus is 1 — 2=6. 



In 1876, Blanford described and figured a form from Persia 

 (Zoology of Persia, p. 54) under the name Mus erythronotus , which 

 he afterwards (that name being preoccupied) changed (A. M. N. H., 

 vii. 1881, p. 162) to Mus arianus. In his " Mammalia " Blanford 

 claims that this form extends into the Indian Region at Gilgit. It 

 seems to me most improbable that a species so variable as M. sylva- 

 ticus should remain unchanged from Ispahan to Gilgit across the 

 whole breadth of Persia and Afghanistan, and I should expect rather 

 to find at Gilgit either True's subspecies griseus or more likely, either 

 wardi or a closely related subspecies. 



* This is the Long-tailed Field Mouse, a common animal all over the British Isles , 

 requently doing much damage to crocus bulbs in the spring.— Eds, 



