Mylomys dybowskii (Pousargues, 1893)

Guy G. Musser & Michael D. Carleton, 1993, Order Rodentia - Family Muridae, Mammal Species of the World (2 nd Edition), Washington and London: Smithsonian Institution Press, pp. 501-755 : 630

Mylomys dybowskii (Pousargues, 1893) . Bull. Soc. Zool. Fr., 18:163.

TYPE LOCALITY: Central African Republic (= French Congo), Kemo River .

DISTRIBUTION: Guinea (Mt Nimba), Ivory Coast, Ghana, S Cameroon, Congo, Central African Republic, W, N and E Zaire, Rwanda, Tanzania, Kenya, Uganda, and S Sudan.

SYNONYMS: alberti, christyi, cuninghamei , lowei , massaicus , rex , richardi, roosevelti .

COMMENTS: Hatt (1940a) noted that the cotypes of dybowskii are examples of Mylomys and not Pelomys , under which the name had been listed ( Ellerman, 1941), and selected a lectotype. The identity was verified by F. Petter (1962b). Significance of geographic variation in chromatic and morphological traits has yet to be assessed by critical systematic revision; whether the genus is monotypic or contains more than one species is unresolved. Chromosomal data for sample from Central African Republic reported by Matthey (1970), and those from Mt Nimba ( Guinea) provided by Gautun et al. (1986).

The taxon rex , represented only by the holotype, a skin without skull from Kaffa in C Ethiopia, was described by Thomas (1906a) as a species of Arvicanthis , but later "provisionally considered as a giant member of Desmomys " ( Thomas, 1916a:68). Dieterlen (1974) challenged the validity of rex , but Yalden et al. (1976) pointed out the features distinguishing the holotype from samples of D. harringtoni , and treated rex as another distinctive species endemic to Ethiopia. Our study of the holotype skin reveals it to be a large and probably old adult of Mylomys that is not as brightly pigmented as most samples of that genus. Whether the holotype actually came from Ethiopia, or represents a separate species of Mylomys are unknown; we provisionally list rex in the synonymy of M. dybowskii .