CONTENTS OF PART XVI. 



RODENTIA (Rodents) — 

 Group Orcadensis — 



The Orkney Grass Mouse 



Locally Extinct Voles 

 Genus Mimomys 

 Genus Arvicola 



The British Water Rat 



The South British Water Rat 



The Black Water Rat 



Sub-family Murince 

 Genus Apodemus 



The English local names have been revised in part by Mr W. W. Skeat, 

 M.A. {assisted by the late Professor W. W. Skeat), and in part by 

 Mr C. M. Drennan, M.A. Land., late Scholar Emm. Coll. Camb. ; 

 the Celtic and Gaelic names by Dr E. S. Quiggin, M.A., Ph.D., 

 Fellow and Lecturer in Modern Languages and Celtic of Gonville 

 and Caius College, Cambridge; while a list of Scottish Gaelic 

 names has been supplied by Mr C. H. Alston. Much information 

 has been taken from Mr G. S. Miller's recently published 

 " Catalogue of the Mammals of Western Europe^' the use of the 

 MS. and proof s of which before publication was kindly permitted 

 by the Trustees of the British Museum of Natural History. 



457 

 467 



473 

 476 



478 

 481 



483 



497 

 502 



ILLUSTRATIONS 



Full- PAGE {^Coloured and Black and White). 



British MicrotincE (Skins); (i) Microtus hirtus ; (2) M. agrestis 



neglectus ; (3) M. orcadensis ; (4) M. agrestis exsul. {Coloured!) 

 Water Rats. Crown Views of slightly worn Cheek-Teeth of Muridce. 



Figures in Text. 



Right Cheek-Teeth of Microtus orcadensis orcadensis ; Right of m.^^ of 



M. 0. sandayensis ; posterior palate of Jkf. 0. sandayensis. 

 Plan of Nests of Orkney Vole. 



Fossil Right m^ of M. anglicus and of Microtus ratticeps. 

 Chionomys nivalis . A, left m-^ ; B, left tn^ ; crown view. 

 Pitymys subterraneus. Right upper and Left lower Cheek-Teeth. 

 Cheek-Teeth of Mimomys. 



Dorsal View of Adult Skull of Arvicola amphibus. 

 Spoor of Water Rat in Snow. 

 Water Rat Burrows and Refuges. 



