Larval Flukes associated with the Cercariae of Clonorchis sinensis in Bithynoid Snails in China and Adjacent Territory

1. Eleven new species of cercariae are described from China. Of this number ten have been obtained from species of bithynoid snails and one from Planorbis möllendorfi. 2. One of these species, Cercaria beatifica, a heterophyid larva, needs to be differentiated from the cercaria of Clonorchis sinensis, which develops experimentally in the same mollusc. 3. The forms described are much more common parasites of bithynoid snails than is the larva of Clonorchis. 4. Wherever it has been possible the larval characters, particularly those of the excretory system, have been utilised to show the relationship of the cercariae to adult groups.