Isthmomys Hooper and Musser 1964

Isthmomys Hooper and Musser 1964, Occas. Pap. Mus . Zool., Univ. Michigan, 635: 12.

Type Species: Megadontomys flavidus Bangs 1902

Species and subspecies: 2 species:

Species Isthmomys flavidus (Bangs 1902)

Species Isthmomys pirrensis (Goldman 1912)

Discussion: Reithrodontomyini. Species associated here were originally classified in Megadontomys, used either as a genus or as a subgenus of Peromyscus (Osgood, 1909) . Isthmomys was later diagnosed as a subgenus of Peromyscus (Hooper and Musser, 1964b) and maintained at this rank by Hooper (1968); diagnosis emended and accorded generic status by Carleton (1980, 1989). Sister-group relationship with Megadontomys proposed by Carleton (1980) but unsupported by chromosomal banding data (Stangl and Baker, 1984b). Aspects of morphology considered by Carleton (1973, 1980), Hooper and Musser (1964b), and Linzey and Layne (1969, 1974); karyology by Stangl and Baker (1984b).