PREFACE 



The Voles and Lemmings form a group that presents many 

 difficulties to the systematist ; they are also of special interest 

 in relation to the dental evolution of the Simplicidentate Rodents. 

 Mr. Hinton's monograph is the result of an intensive study 

 that began more than twenty-five years ago; his work on the 

 fossil species has led him to certain conclusions as to the sequence 

 of Pliocene and Pleistocene deposits and the date of the Glacial 

 Period, which were put forward at the 1925 meeting of the 

 British Association, and will be published in the next number 

 of the Proceedings of the Yorkshire Geological Society. This 

 first volume includes a general account of the Microtinss and a 

 systematic revision of 14 of the 31 genera; the second, the 

 preparation of which is well advanced, will conclude the work. 

 Attention may be called to Mr. Hinton's views as to the impor- 

 tance of habits and environment in specific differentiation ; when 

 ideas of this kind are derived from a profound and intimate 

 study of a group they should be worthy of serious consideration. 



The author wishes to acknowledge his indebtedness to Mr. A. C. 

 Savin of Cromer for the loan, without restriction of time, of a 

 very large collection of Microtine remains from the Cromerian 

 Beds; also to Mr. W. J. Lewis Abbott, Miss D. M. A. Bate, Dr. 

 H. P. Blackmore, Dr. Frank Corner, Mr. J. Wilfrid Jackson, 

 Mr. A. S. Kennard, Dr. H. C. Male, the late Dr. C. I. Forsyth 

 Major, Dr. L. S. Palmer, Prof. S. H. Reynolds, Dr. R. F. Scharff, 

 Dr. 0. Wettstein, and Mr. Gilbert White for gifts or loans of 

 fossil material. Thanks are also due to the Geological Survey 

 of England and Wales, the Irish National Museum, the Royal 

 Scottish Museum, the Museums of Cambridge University, Bristol, 

 Norwich, Ipswich, Taunton, and Wells, the Bristol University 

 Spelseological Society and the Vienna Museum, for the loan of 

 material. 



The author wishes to thank many friends for assistance of 

 various kinds, including Mr. Oldfield Thomas, Mr. R. Oldfield, 

 Mr. B. B. Woodward and Mr. C. D. Sherborn, but particularly 



