610 RODENTIA 



coloui' pattern will at once distinguish this animal from all other 

 European rodents. 



1. Malcoci, Dobrudscha, Purchased (Pruliere) (p). 86. 4. 2. 5. 

 Roumania. 



1. Rustchuk, Bulgaria. Dr. Knud Andersen (p). G. 5. 17. 1. 



Sub-Family MICROTIN^. 

 1906. Microtinx Miller, Nortli Amer. Fauna, No. 12, p. S. 



Geographical distrihution. — Northern portion of both hemi- 

 spheres, south to Mexico, northern India, and the Mediterranean 

 coast of Europe 



Characters. — Murine rodents with definitely prismatic, 

 hypsodont or rootless, flat-crowned molars. 



BemarJcs. — The sub-family Microtinse contains about thirty 

 groups, genera or sub-genera, the status of which is still 

 imperfectly understood. These fall naturally into three main 

 sub-divisions, the Lemmi, characterized by the shortness of the 

 lower incisor, the root of which remains on the lingual side of 

 the molar alveoli, the Microti, containing the true voles, and the 

 ElJohii, the last highly modified for underground life. The 

 Lemmi and Microti are represented in western Europe, the first 

 by two living genera, the second by four. Fossil and sub-fossil 

 remains of membei-s of the sub- family are found throughout 

 this region, some of them representing genera now extinct. 



KEY TO THE EUROPEAN GENERA OF MICBOTINJE. 

 Root of lower incisor lying entirely on lingual side of 

 molar teeth (Lemmi). 

 General form vole-like ; feet slender (normal) ; palms 

 and soles with well developed functional (normal) 



tubercles Mijopus, p. 611. 



Ger eral form short and heavy ; feet broad, the 

 metapodials shortened and ungual phalanges 

 lengthened ; palms and soles with rudimentary, 

 non-functional tubercles concealed by a dense 



growth of stiffened hairs Lcmmus, p. 614. 



Root of lower incisor extending to outer side of molar 

 teeth {Microti). 

 Bony palate terminating posteriorly in a thin-edged 



shelf; molars rooted in adult Evoioimjs, ]). 623. 



Bony palate terminating posteriorly in a sloping 

 median ridge and two lateral pits. 

 Sole with six well developed tubercles ; mammse, 8. Microtus, p. 658. 

 Third upper molar with three re-entrant angles 



on inner side Microtus, p- 659. 



Third upper molar with two re-entrant angles on 



inner side Chionomys, p. 712. 



Sole with five well developed tubercles ; mammse, 

 8 or 4. 

 First lower molar with first outer and first 

 inner triangle communicating ; mammse, 4 ; 

 general form modified for underground life... Pitymys, p. 752. 

 First lower molar with first outer and first inner 

 triangle not communicating ; mammas, 8 ; 

 general form modified for aquatic (rarely 

 subterranean) life Arvicola, p. 723. 



