1. Beauchamp, P. de., CR Soc. Biogéog., 17, 7 (1940).
2. Beauchamp, P. de., in Traité de Zoologie (edit. by Grassé, P.), 4 (Masson et Cie, Paris, 1965).
3. Reynoldson, T. B., Adv. Ecol. Res., 3, 1 (1966).
4. Dahm, A. G., Taxonomy and Ecology of Five Species Groups in the Family Planariidae (Diss., Univ. Lund).
5. Ball, I. R., J. Fish. Res. Bd. Canada, 26 (in the press).