NATURAL SCIENCES OF PHILADELPHIA. 187 



of tlie cond^yle (unique among Arvicolinae). Bony palate ending 

 in a straight flat shelf opposite middle molars, the whole space 

 between last molars thus left open. General form arvicoline, but 

 ears distinctly overtopping the fur as in Min-inse. A strong 

 genus, linking the two subfamilies. There are many peculiarities 

 besides these given. 



1. Evotomys rutilus, (Pall.) Coues. 



Syn. Mus rutilus. Pall., K Sp. Quad. Glir. 1778, 246, pi. xiv. B. 

 Arvicola gapperi, Dall, Alaska and its Resources, 1870, 577. 



Hab. Arctic, circumpolar. Southward in this country this spe- 

 cies shades into the following variet}' : 



la. Evotomys rutilus, var. gapperi, (Vig.) Coues. 



Syn. Arvicola grippei'i, Vig. Zool. Journ. v. 1830, 204, pi. 9. (Canada.) 

 Arvicola {Hypudaus) gapijeri, Baird, M. N. A. 1857, 518. 

 Arvicola fulva, Aud. and Bach., J. A. N. Phil. viii. 1842, 295. 



(Name preoccupied.) 

 Arvicola dekayi, Aud. and Bach., Q. N. A. iii. 1854, 287 (same as 

 their A. fulva of 1842). Excl. syn. '' oneida DeKay" which belongs 

 to A. riparius. 



Hab. Northern frontier of IJnited States, from Atlantic to 

 Pacific, and adjoining belt of British America. South to Massa- 

 chusetts. 



Obs. This species and its variet}^ are distinguished at a glance 

 by the prominent ears and chestnut coloration. 



Genus VI. ARVICOLA, Lacep., emend. 



Syn. Mus, sp., Linn., Syst. Nat. i. 1766, et auct. nntiq. Mures ciinicn- 

 larii, Pall., N. Sp. Glir. 1778, Ti.Lemmus, Linck, Fischer, et al. 

 Myodes, Pall, Zoog. R. A. i. 1811, 172 (not Myodes of Selys-L., 

 1839, which = 7/?/^j/(ffe(<s, Keys, and 'E\&.^. = Evotomys, Coues). 

 Arvicola, Lacepede, Tabl. 1803, et auct. recent, (includes amphibius 

 and arvalis). Hypudceus, 111., Prod. 1811 (not of Keys, and Bias., 

 nor of Baird. Includes lemmus, ampMbius and arvalis), Myonomes, 



Rafinesque, (type "Wilson's Meadow 1sIo\\s,q'' = Arvicola 



pennsylvanica of Ord.). Psammomys, Le C, Ann. Lye. N. Y. 

 1829, 132 (type pinetorum; not oiHueppel). Pitymys, McMurtrie, 

 ed. Cuvier, i. 1831, 434 (type A. pinetorum). Hemiotomys, Selys-L., 

 Etudes, 1839, 85 (anijiJubius, terrestris, etc.). Microtus, Selys-L., 

 Etudes, 1839, m.Pinemys, Lesson, Nouv. Tabl. R. A. 1842, 12 

 (type pinetorum). Hemiotomys, Bd., M. N. A. 1857, 515 (type 

 A. riparius, Ord.). Pedomys, Bd., op. cit. 517 (type A. austerns, 

 Le C). Ghilotus, Bd., op. cit. 516 (type oregonus, Bach.). 



