540 MURID^— APODEMUS 



THE ST KILDA FIELD MOUSE, 



APODEMUS HIRTENSIS, Barrett-Hamilton. 



1899. Mus HIRTENSIS, G. E. H. Barrett-Hamilton, Proc. Zool. Soc, London, 1899, 

 81, pi. ix., fig. I, reprinted in Ann. Scott. Nat. Hist., 1899, 129; described from 

 St Kilda : type specimen No. 94.7.16.1 of British Museum collection, Barrett- 

 Hamilton, Ann. Scott. Nat. Hist., 1906, i. ; {Apodemus) Miller, Catalogue, 825, 1912. 



1900. Mus SYLVATICUS HIRTENSIS, G. E. H. Barrett-Hamilton, Proc. Zool. Soc, 

 London, 1900, 404 ; Johnston ; Millais ; Trouessart. 



Distribution and history : — This field mouse is only known from 

 St Kilda, upon which mice of some sort have been long known 

 to exist (Seton, St Kilda, Past and Present, 1878, 132) ; it inhabits the 

 main island — Hirta — and the adjacent islets, Soay and Dun. Steele 

 Elliott, in an account of a visit to St Kilda given at a meeting of the 

 Birmingham Nat. Hist, and Philosophical Society on 13th November 

 1894 (^Proceedings, April 1895, 135 ; and Zoologist, 1895, 282), mentioned 

 the occurrence of a peculiar field mouse on the island. Unfortunately 

 he secured only one specimen — " by far the most interesting of all my 

 captures " — which was placed in spirit and forwarded to Harting. It 

 was thought advisable to wait for further specimens before deciding on 

 the status of this animal ; but, for some reason, Harting failed to record 

 the capture in the Zoologist. In January 1895 de Winton mentioned 

 {Ann. Scott. Nat. Hist., 1895, 53) the occurrence of "The Wood-Mouse 

 {Mus sylvaticus) " on St Kilda. Later, when de Winton described his 

 Mus hehridensis {Zoologist, October 1895, 369), Steele Elliott, not 

 suspecting the possibility that hirtensis and hehridensis might be 

 distinct, wrote {Journ. cit., 1895, 426, and 1896, y&) claiming priority for 

 the discovery. De Winton at once pointed out {Journ. cit., 1895, 446) 

 that his own description of hehridensis was not applicable to the mouse 

 taken by Steele Elliott at St Kilda. In 1898 Barrett-Hamilton's interest 

 was awakened by the remarkable appearance of Steele Elliott's mouse, 

 and he induced Henry Evans to land on St Kilda and trap further speci- 

 mens. On the material so obtained Barrett-Hamilton based his Mus 

 hirtensis} The habits of this mouse have been described by J. Waterston 

 {Ann. Scott. Nat. Hist., 1905, 199), and Eagle Clarke's recent work has 

 greatly extended our knowledge of it {Journ. cit., June 1914, 124). 



Description: — A. hirtensis is a large mouse with long feet and 

 rather short ears, distinguished from its closest ally, A. hehridensis, by 

 its larger size, relatively longer ears, occasionally darker ventral colora- 

 tion, and considerably larger skull. 



The colour of the back and flanks is nearly as in sylvaticus ; the 

 under-surface is sometimes heavily washed with buffer yellowish-brown, 

 which tint merges laterally in that of the flanks, so that there is no well- 

 defined line of demarcation. It seems, however, that this is not the 

 ' Barrett-Hamilton, Ann. Scott. Nat. Hist., 1906, i. 



