﻿22 



NORTH AMERICAN FAUNA. 



[No. 12. 



Blasius. His classification of tlie subdivisions of Microtus is as 

 follows : 



Genus Arvicola : 



Subgenus Hypudmis {(lapperi). 

 Subgenus Arvicola (typical voles). 



Section Bemiotomys (most of the American species and the European 



agrcsi'is). 

 Section Chilotus (oregoni). 

 Section Fedomys (ausferus). 

 Section Pifymys {pinetorum). 



Baird's subgenera Hypudmis and Arvicola are equivalent to the 

 genera Evotomys and Microtus of the present paper, while his sections 

 Chilotus, Fedomys, and Pity my s are equal to the subgenera of the same 

 names. The section Hemiotomys of Baird is the Arvicola of De Selys 

 Lougchamps, and the subgenus Microtus of the present paper. 



In 1867 Fatio published a classification of the European voles in a 

 paper entitled 'Lcs Campagnols du Bassin du Leman.' This arrange- 

 ment is essentially the same as that of Blasius. Fatio, however, recog- 

 nizes Hyimdams {=Uvotomys) as a full genus, and raises the second of 

 Blasius's two sections of the subgenus Arvicola to the rank of a sub- 

 genus, while the first he unites with Microtus terrcstris, M. nivalis^ 

 and M. ratticeiis to form the subgenus Fraticola. He also arbitrarily 

 changes the names of certain groups. His classification is as follows: 



Genus Hypudanis (glareolus) . 

 Genus Arvicola. 



Subgenus Praiicola (' amjjhihius,' nivalis, arvalis, ratticeps, campestris). 

 SnhgenvLS Sylvicola {agrestis). 

 Subgenus Terricola {subterraneus, savii). 



The subgenus Terricola and the genus Ilypudwtis are equal, respec- 

 tivel,y, to the subgenus Pitymys and the genus Evotomys of the present 

 paper. The subgenus Sylvicola is equivalent to the snbgenns Agricola 

 of Blasius, like it containing the i)entamerodont species of the subgenus 

 Microtus. The subgenus Praticola includes the type species of both 

 Arvicola and 2[icrotus, together with three other tetramerodont species 

 of the latter. 



In 1874 Dr. Goues published, in the Proceedings of the Academy of 

 Katural Sciences of Philadelphia, an abstract of his monograph of 

 the ISorth American Murid?e, which appeared in full in Tolume XI 

 of the Eeport of the United States Geological Survey of the Terri- 

 tories (Monographs of ]Srorth American Eodentia). Here he presented 

 a classification of the American Microtiiuv based primarily on Baird's 

 review of the group. The dili'erences between the arrangements adopted 

 by Baird and Goues are so slight that a few words only are necessary 

 in regard to the latter. Dr. Goues recognizes the red-backed mice as a I 

 distinct genus, which he calls Evotomys, after showing that the name I 

 Hypudceus generally used for the groui) is untenable. The subgenera I 

 of Microtus adopted by Dr. Goues are exactly equivalent to Baird's 1 



