Chromosomal data presented by Viegas-Péquignot et al. (1983) in context of chromosomal phylogeny of selected murines; protein electrophoretic data analysed by Iskandar and Bonhomme (1984). Karyotype of Senegal sample reported by Granjon et al. (1992). Karyotypes are geographically variable: 2n = 50 in Senegal, 2n = 58 in Côte d’Ivoire, and 2n = 52 in Central African Republic, suggesting that more than one species is represented. Furthermore, specimens of shortridgei are darker than the others and have much larger molars. Ingoldby (1929) was impressed with the traits of acomyoides, which he named as a species, and he pointed out the orthodont configuration of its incisors, which contrasted with the proodont facies of all the other named forms. The significance of geographic variation in fur color, craniodental traits, and chromosomal characteristics has to be assessed in a systematic revision of the genus, which should also employ data from DNA sequences.

The Ethiopian record is documented by Lavrenchenko (1993), who also provided range map of the species and description of the phallus. Spermatozoal morphology described by Baskevich and Lavrenchenko (1995) and Breed (1995a). Grubb et al. (1998) reviewed populations in Ghana and Sierra Leone. Range in Southern African Subregion mapped by de Graaff (1997p), who also provided short review.