Class [Mammalia] Linnaeus, 1758 - mammals
   Order Rodentia Bowdich, 1821 - rodents
     Family Muridae Batsch, 1788 - rats, mice, hamsters, voles, lemmings, and gerbils
       Subfamily Arvicolinae Gray, 1821 - voles
         Genus Phenacomys Merriam, 1889 - heather vole
           1 Phenacomys albipes - white-footed vole
           2 Phenacomys intermedius Merriam, 1889 - heather vole
           3 Phenacomys longicaudus - red tree vole