Class [Mammalia] Linnaeus, 1758 - mammals
   Order Rodentia Bowdich, 1821 - rodents
     Family Muridae Batsch, 1788 - rats, mice, hamsters, voles, lemmings, and gerbils
       Subfamily Hesperomyinae Murray, 1866 - New-World mice and rats see Subfamily Sigmodontinae Wagner, 1843
         Genus Rheomys Thomas, 1906 - water mice
           1 Rheomys mexicanus Goodwin, 1959 - Mexican water mouse
           2 Rheomys raptor Goldman, 1912 - Goldman's water mouse
           3 Rheomys thomasi Dickey, 1928 - Thomas' water mouse
           4 Rheomys underwoodi Thomas, 1906 - Underwood's water mouse