4;6 MURID^— ARVICOLA 



teeth of this form resemble those of M. intermedius in pattern, 

 but their roots are developed only in senile stages of growth. 

 Remains of still other species of Mimomys are known from the 

 late Pliocene deposits, but these have not yet been satisfactorily 

 defined.] 



Genus ARVICOLA. 



1799. ARVICOLA, Lac^pfede, Tab. des Mammiferes, 10, based on amphibiusj Lataste, 



Le Naturaliste, October 1883, 349 (sub-genus) ; Miller, N. Amer. Fauna, No. 12, 



66, 23rd July 1896 (sub-genus) ; Miller, Ann. and Mag. Nat. Hist., February 1908, 



195 (genus). 

 1836. Hemiotomys (sub-genus), E. de Selys-Longchamps, £jjaz Monographtque sur 



les Campagnols des environs de Liige, 7 (part), based on Arvicola {=-Microtus) 



fulvus = M. arvalis and A. terrestris ■= amphibius. 

 1857. Paludicola (sub-genus), J. H. Blasius, Sdugethiere Deutschlands, i., 333 



(part) ; based on amphibius = scherman, nivalis, and ratticepsj preoccupied by 



Paludicola of Wagler, 1830, a genus of amphibians. 

 1867. OCHETOMYS, L. J. Fitzinger, Sitzungsb. k. Akad. Wiss. (Wien), Ivi., June, 



103 ; based on the Water Rats of Europe. 

 1867. Praticola, Victor Fatio, Les Campagnols du Bassin du Leman, 36 (part) ; 



based on amphibius = scherman, nivalis, arvalis, ratticeps, and campestris 



{ = arvalis) ; preoccupied by Praticola of Swainsson, 1837, a genus of birds. 



Synonymy :— The full synonymy is given in Miller's Catalogue. 

 The name Arvicola was for a time used to designate a large 

 genus, including the bulk of the Microti. It is antedated in 

 that sense by Microtus, but proves to be available for the 

 Water Rats. 



Although it is convenient to treat the Water Rats as a 

 genus, they are not very sharply differentiated from the Grass 

 Mice {Microtus), from which they differ mainly in their larger 

 size ; relatively longer tails ; in possessing lateral musk-glands ; 

 normally five, instead of six, plantar pads ; and nv" with 3 + 3 

 salient angles and 2 + 2 infolds, as in Chionotnys. Many of the 

 species are aquatic ; but others are more or less subterranean. 

 The fur is long and suitable for commercial purposes, but, doubt- 

 less owing to the small size of the animals, is not widely used. 



Distribution :— The Water Rats have a wide range in the 

 Palaearctic Region, north of the Himalayas, from Norway (to 

 the outermost Skerries) and Wales, at least to the river Amoor 

 (Schrenck), and from the Norwegian shores of the Arctic 

 Ocean with corresponding zones in Siberia to the Mediterranean 

 coasts of Spain and France, Central Italy, Bosnia, Rumania, 



