Sources vary on how many species the genus contains. Some consider the rubber boa, C. bottae, to be the sole member of the genus, although recent research has included the rosy boa, C. (Lichanura) trivirgata. In addition, some experts consider the southern rubber boa, C. umbratica to be a subspecies of C. bottae. The strangest inclusion, however, must be that of the Calabar python, C. (Calabaria) reinhardtii, which is found half way around the world from the others.
^ abcdefMcDiarmid RW, Campbell JA, Touré T. 1999. Snake Species of the World: A Taxonomic and Geographic Reference, vol. 1. Herpetologists' League. 511 pp. ISBN 1-893777-00-6 (series). ISBN 1-893777-01-4 (volume).