Rhagomys is a genus of South American rodents in the tribe Thomasomyini of the family Cricetidae. Two species separated by about 3100 km are known, from southeast Peru and Bolivia east of the Andes, and in the Atlantic Forest of southeast Brazil. An undetermined species of Rhagomys has also been reported from Mato Grosso in central Brazil. The species are as follows: \n* Long-tongued arboreal mouse (Rhagomys longilingua) \n* Brazilian arboreal mouse (Rhagomys rufescens)