During periods of low-land exposure the connection between Isla de la Juventud and the Guaniguanico mountain range (Furrazola-Bermúdez et al., 1964) could have allowed the dispersal of R. cylindraceus to the southern part of the western Cuba (i.e. Gua- nimar) and more recently from Isla de la Juventud to the south of the Matanzas province (i.e. Facundo Lagoon).