Two species are recognised in this genus: U.pilirostris and U. talpoides. Both are restricted to Japan where they occur in montane habitats, particularly regions of coniferous forest up to 2000m. Both species are reported to be plentiful but do not occur on the plains.
U. pilirostris and U. talpoides are considered as "Lower Risk" sub category "Least Concern" by the IUCN.