ARVICOLA 385 



considerably newer than the High Terrace. These niammaha 

 are such that we cannot imagine them to have survived the rigours 

 of glaciation in this region ; and had they ever been driven out of 

 this country in consequence of chmatic changes, or from any 

 other cause, they would never have returned to it in High Terrace 

 or early Middle Terrace times.^ 



Genus : 14. ARVICOLA Lacepede. 



1799. Arvicola Lacepede, Tab. des Mammiferes, p. 10. 



1836. Hemiotomys do Selys-Longchamps, Essai monographique sur 

 les Carapagnols des environs de Liege, p. 7 (in part; "section" 

 based upon " Arvicola fulvus " [= Microtus arvalis] and " Arvicola 

 amphibius" [= ^4. terresiris]). 



1857. Paludicola Blasius, Saiigethiere Deutschlands, p. 333 (in part); 

 subgenus of ^''Arvicola" [^Microtus] based upon ''^Arvicola 

 am.phibius" [— A . [scherman], "Arvicola" [=: Microtus] nivalis, 

 and "Arvicola" [= Microtus] ratticeps. Preoccupied by Palu- 

 dicola Wagner, 1830 (Amphibia). 



1867. Ochetomys Fitzinger, .Sitzungsb. Math.-Naturwiss A. k. Akad. 

 VVissensch., Wien, 56, p. 47 ; based primarily upon the water rats 

 of Europe. 



1867. Fraticola Fatio, Les Campagnols du Bassin du Leman, p. 36 

 (in part); subgenus based upon Arvicola " ampkibius" [= A. 

 scherman], [Microtus] nivalis, and [M .] arvalis, [M.] ratticeps and 

 [M.] " campestris " [= M. arvalis]. Preoccupied by Praticola 

 iSwainson, 1837 (Aves). 



1883. Arvicola Lataste, Le Naturaliste, 2, p. 349 (subgenus of 

 Microtus) ; Miller, N. Amer. Fauna, No. 12, 1896, p. 66. 



1908. Arvicola Miller, Ann. Mag. N.H., [SJ, 1, p. 195 (genus) ; Trouessart 

 Faune Mamm. d'Europe, 1910, p. 193; Miller, Catal. Mamm. 

 W. Europe, 1912, p. 723. 



Genotype. — Mus amphibius Linnaeus. 



Range. — Widely distributed in the Palsearctic Region, ranging 

 from the Mediterranean coast of Europe, Asia Minor, Palestine 

 and the northern base of the Himalayas, northwards to the Arctic 

 coasts of Europe and Asia, and from Great Britain eastwards to 

 the Amur River at least. 



Characters. — General form nearly as in Microtus, but size 

 always large (in recent species hind-foot 22-35 mm. ; condylo- 

 basal length 32-44 mm.) ; tail about half the length of head and 

 body or more ; flank glands present in adult males and sometimes 

 in both sexes ; plantar tubercles more or less reduced. 



Skull strongly built, the anterior portions of the temporal 

 muscles powerfully developed, producing in the adults of all living 

 species, and of fossil species from early Middle Terrace times 

 onwards, well-marked post-orbital squamosal crests and a more or 

 less salient linear median interorbital crest. Pterygoid fossae 



1 See HiXTOX, Rivers and Lakes, 1924, pp. 49-81. Proc. Yorkshire 

 Geol. Soc. (forthcoming number); and Proc. Geol. Assoc, 21> 1910, p. 499. 



