1874.] ON FOSSIL AKVICOLID^E. 461 



(as Prince Bonaparte and M. Pomel), who have attributed specific 

 value to slight cranial differences. In accordance with these views 

 we have thought it necessary considerably to reduce the number of 

 recorded species. 



Remains of Arvicolidce have been found in the upper beds of the 

 Norwich Crag series, in the breccia of the Mediterranean islands, in 

 brick-earths and other deposits of the Drift period, and in many 

 bone-caves in England, France, Belgium, Germany, and Italy. When 

 not identical with the species now inhabiting these countries, they 

 show affinity, as might be expected, with North-European and 

 Siberian forms ; and the two species of restricted Myodes, in parti- 

 cular, are very characteristic of the glacial fauna of which they were 

 members. 



Before proceeding to the enumeration of the species, we have to 

 express our best thanks to those who have assisted us with informa- 

 tion and the loan of specimens, especially to the Committee of the 

 Norfolk and Norwich Museum, to Sir Charles Lyell and Prof. Owen, 

 Messrs. Boyd Dawkins and Sanford, Mr. Moore, of Bath, Messrs. 

 Southwell, Harmer, and Reeve, of Norwich, and Mr. Bidgood, of 

 Taunton. 



I. Arvicola glareolus (Schreber). 



1846. Arvicola pratensis, Owen, Br. Foss. Mamm. p. 208, fig. 78. 

 1852 (?). Arvicola delarbrei (sp. n.), Pomel, Ann. Sc. de l'Au- 

 vergne, xxv. p. 362. 



1855. Arvicola glareolus, Hensel, Zeits. d. Deutsch. Geol. Ges. 

 vii. p. 483. 



1866. Arvicola pratensis, Boyd Dawkins & Sanford, Pleistoc. 

 Mamm. (Introd.) p. xxxvi. 



1869. Arvicola pratensis, Boyd Dawkins, Q. J. Geol. Soc. xxv. 

 p. 194. 



1870. Arvicola glareolus, Sanford, ibid. xxvi. p. 124. 



The Red Field-Vole was first noticed as a fossil species by Prof. 

 Owen, under Baillon's name of A. pratensis, some remains obtained 

 by Mr. McEnery from Kent's Hole, now in the British Museum, 

 having been identified by Mr. Waterhouse. M. Pomel's A. delar- 

 brei, from the Breche de Coudes, is stated to be a little larger than 

 A. glareolus, and to differ slightly in the details of the molars ; but 

 these are points in which individual variations are constantly found 

 in the recent animal. The species appears to have been rare in 

 England in Pleistocene times ; Mr. Boyd Dawkins added no new 

 localities ; and Mr. Sanford had only seen two jaws, one of which, 

 from Button Cave, is in the Taunton Museum. Mr. C. Moore has 

 found a detached first lower molar in a cavern near Bristol; we 

 have a jaw from Wookey Hole in our own collection ; and a frag- 

 mentary jaw and some separate teeth from the Norfolk forest-bed 

 series are in the Norwich Museum. 



A. glareolus has a recent European range north of the Alps and 

 Apennines, extending to within the Arctic Circle and to the Ural 



