Phaulomys Thomas, 1905 . Ann. Mag. Nat. Hist., ser. 7, 15:493.

TYPE SPECIES: Evotomys smithii Thomas, 1905 .

COMMENTS: Originally described as a subgenus of Evotomys (= Clethrionomys) and included in Eothenomys by most workers (Aimi, 1980; Corbet, 1978c). Kawamura (1988), however, reinstated Phaulomys as a genus containing the two species listed below. Although the extant species have rootless molars, they can be derived through a transitional series of late Pleistocene samples from the middle Pleistocene Clethrionomys japonicus, which has molars with definite roots. Study of the variation in molar and external traits among species of Eothenomys and Anteliomys also led Tanaka (1971) to recognize Phaulomys as a genus distinct from Eothenomys. Chromosomal analyses of smithii suggest that Clethrionomys and Phaulomys have been derived from a common ancestor (Ando et al., 1988). The removal of Japanese Phaulomys from Eothenomys, whose species-diversity centers in the mountains of China, and its proposed association with Clethrionomys is zoogeographically plausible and outlines a precise hypothesis that can be tested by analyses of other data sets. Aimi (1980) retraced the complex taxonomic history of species allocated to either Evotomys, Clethrionomys, Anteliomys, Phaulomys, or Eothenomys.