390 MB. G. E. II. BARRETT-HAMILTON ON [Apr. 3, 



representative, and I could not hear of it in Kamchatka ; but its 

 absence from the latter country is not surprising when it is 

 considered that the peninsula, as shown by its general fauna, has 

 probably been isolated as an island until recent times, and further 

 that we are not aware of the presence of Mus sylvaticus in the 

 two main roads thither, in Chukchiland or the Kuril Islands. 



In Asia Minor it was found by Menetries amongst the moun- 

 tains of Talycbe, by Canon Tristram on the plains of Palestine, 

 and Danford caught a specimen " while running about on the 

 surface of the deep snow," considerably above the tree-growth l . 

 As a contrast to this, one has been trapped by Mr. GK H. Caton 

 Haigh in Wales among the rocks on the shore near the mouth of 

 an estuary, so that it seems equally at home in extremely varied 

 localities. 



In spite, however, of its wide distribution and comparative 

 disregard of extremes of climate and environment, it is one of 

 those mammals which do not seem to have reached Tunis, Tripoli, 

 or Egypt. 



The southern boundary of its range in Asia is uncertain. It 

 has been reliably recorded from Waklnin on the Upper Oxus ; from 

 Kashgar, in Eastern Turkestan ; from Gilgit in the Upper Indus 

 Valley; from Cherra Puuji, India; from Kashmir; and from 

 Kuatun, in North-west Fokien, Eastern China. It thus reaches 

 the confines of the Orieutal Kegion at more than one locality. 



Its presence in such isolated, yet widely separated, islands as 

 Iceland and Corsica (if, indeed, it be native in the former), seems 

 to mark it as a species which has for long maintained a wide area 

 of distribution, aud which is of sufficient age to have already 

 occupied the greater part of its present geographical range when 

 the British Islands and their appendages, at least as far as the 

 Shetlands, Outer Hebrides, St. Kilda, and Ireland, still formed part 

 of the Continent of Europe, and when there existed a free land- 

 passage from Europe to North Africa by means of substantial land- 

 bridges where now only islands remain. Japau alone seems to be 

 old enough to have given it time for specific modification. This 

 supposition gains support from the fact" that its bones have been 

 found in numerous caves on the Continent as well as in the English 

 Forest-Bed of Norfolk, and elsewhere, as in the Ightham Fissures 

 of Kent, and that we have no trace of its ancestry, the 

 Pleistocene species Mas orthodon Hensel and Mas lewisi E. T. 

 Newton 3 being at least as highly specialized as itself. 



The question as to whether this Mouse could be indigenous to 

 Iceland I left an open one, since it seems likely that the connection 

 between that island and the Shetlands must have been of far more 



1 Proc. Zool. Soc. 1877, p. 279. 



2 See A. Nehring's " Uebersieht iiber vierundzwanzig tnitteleuropaische 

 Quartar-Fauuen," Zeitschr. d. deutsch. geol. Gesellsch. Ed. xxxii. 1880, pp. 4(i8- 

 509; also Brandt & J. N. Woldrich's " Diluviale europaisch-nordasiatisclie 

 Saugothierfauna und ihre Beziehimgen zum Menschen," Mem. Aead. Imp. Sci. 

 St. Petersbourg, xxxv. I. p. (39 (1887). 



3 Quart. Journ. Geol. Soc. vol, 1. pt. 2, no. 198 (May 1, 1894). 



