Mastomys Thomas, 1915 . Ann. Mag. Nat. Hist., ser. 8, 16:477.

TYPE SPECIES: Mus coucha Smith, 1834 .

COMMENTS: The historical taxonomic use of Mastomys as a genus or subgenus of either Rattus or Praomys is summarized by Meester et al. (1986). Important to studies of specific diversity, biogeography, and medicine, samples of Mastomys have been examined in several contexts (see reviews by Keogh and Price, 1981, and Skinner and Smithers, 1990). Definition of species by chromosomal and biochemical traits from some regions (Duplantier et al., 1990a; Green et al., 1980; Hubert et al., 1983) has proceeded faster than definitions based on morphology. The result is a new view of species-diversity in the genus, but also an ignorance of morphological limits of those species and their real geographic distributions. Robbins and Van der Straeten (1989) analyzed all the taxa associated with Mastomys but did not allocate any of them to species. We can tie only those associated primarily with South African samples to species following Meester et al. (1986) but otherwise list no synonyms and refer readers to Robbins and Van der Straeten (1989). The genus requires careful taxonomic revision.