A discussion is given of the geographical distribution of the bell-toads (Discoglossidae) and their opalinid parasites and evidence presented (1) that the family, an ancient one, is now decadent; (2) that it arose in eastern Asia and spread westward to Europe by a route north of the Himalaya Mts. {Bombina, Discoglossus, Alytes), northeastward to the Pacific coast of Asia {Bombina) and N. Amer. (Ascaphus), and southeastward across Australia to New Zealand {Liopelma). Ascaphus has no opalinids in the adult, but its tadpoles, which live as larvae over winter, carry Protoopalina stejnegeri* (p. 17), similar to the Protoopalinas of the Euro-Asian bell-toads. Liopelma has no free larval stage and so no opalinids but some Australian hylids and leptodactylids bear Protoopalinas of the subgenus characteristic of the bell-toads and probably left by ancestors of Liopelma in their passage across Australia to New Zealand. A new subfam., LIOPELMINAE (p. 6), is proposed for Bombina, Ascaphus, and Liopelma; another new species of Protoopalina, from Bombina maxina, is mentioned but not named nor described.