EV0T0MY3 211 



1874. Evolomi/s Cones, Proc. Acad. Nat. Sci. Philadephia, p. 186 



(genus); Miller, N. Ainer. Fauna, No. 12, p. 42, 1896. 

 1883. Mijoiles Lataste, Lc Naturaliste, p. 349 and Ann. Mus. Civ. 



Stor.Nat. Geneva, [2], 4, 1887, p. 271 (subgenus of Microtu.s). 

 1900. Eiiotomys Schultz, Zs. f. Naturwiss., 1900, p. 203; Collett, 



Norgcs Pattedyr, 1911, p. 78. 

 1900. Crasconujs Miller, Proc. Wash. Acad. Sci., 2, p. 87 (subgenus 



based on Hypudwus rufocaiius Sundevall); Thomas, P.Z.S., 



1906, p. 863 (genus). 



1902. Eolomijs Forsyth Major, P.Z.S., 1902, 1, p. 107 (misprint for 

 Evoloniys). 



1903. Phaulomys Thomas, Ann. Mag. N.H., [7J, 15, p. 493 (subgenus 

 based on Kvolomys smilhii Thomas). 



1908. Eothenomys Thomas, Abstr. P.Z.S., 1908, p. 45, and P.Z.S., 

 1908, p. 976 (subgenus of Microtus). Not of Miller. 



1911. Caryomys Thomas, Abstr. P.Z.8., 1911, p. 4, and P.Z.S., 1911, 

 p. 175 (subgenus of Microtus); genotype Microtus (Eothenomys) 

 inez Thomas ; Hinton, Ann. Mag. N.H., [9], 11, p. 146, 1923 (genus) ; 

 G. M. Allen, Amer. Mus. Nov., No. 133, 1924, p. 6 (subgenus of 

 Microtus). 



Genotyfe.- — Mus ndilus Pallas. 



Range. — ■Circumpolar in the northern hemisphere, from the 

 Arctic southwards to the Pyrenees, the mountains of Southern 

 Italy, Rumania and Trebizond in Europe; to the Thian-Shan 

 and Kinghan Mountains of Mongolia, Pekin, the Shansi Mountains 

 of North China, the mountains of Hupeh, South China, Korea, 

 Saghalien, and Japan (from Hokkaido to Kiushiu) in Asia; 

 to the mountains of Colorado and North Carolina, and to the 

 coast of North Carolina, in North America. Not known in 

 Greenland, the islands of the Polar Sea, Newfoundland, Spitz- 

 bergen, Novaya Zemlya, Iceland or Ireland. 



Range in time. — The earliest remains of the genus yet dis- 

 covered are those from the late Pliocene or earliest Pleistocene of 

 Britain (Cromer Forest Bed Series and High Terrace of the 

 Thames). Fossil remains occur abundantly in the late Pleistocene 

 and Holocene deposits of Western Europe. 



Characters.- — External form without special peculiarities. 

 Skull with the bony palate terminating posteriorly as a simple 

 transverse shelf; and with the temporal ridges not fused in the 

 interorbital region. Lower incisor relatively short ending in the 

 base of the condylar process below the level of the dental foramen. 

 Cheek-teeth provided with two distinct fangs each in adults. 



The members of this genus are small or medium-sized species. 

 Outwardly they differ from typical voles (genus Microtus) by 

 tlieir rather lighter and more elegant form, larger eyes, more 

 conspicuous ears, and longer tail. The tail is always well 

 clothed with hair and is often provided with a distinct terminal 

 pencil. Hands and feet small and normal, each with five digits ; 

 the thumb very short, provided with a flat nail; the other digits 

 long, armed with small but sharp claws ; palms and soles naked ; 

 palmar pads 5, plantar pads 6. Mammae, 2 — 2 = 8. 



