[Cercaria ogunis n. sp. (echinostomatidae) from Bulinus globosus in West Africa (author's transl)].

Cercaria ogunis n. sp. (Echinostomatidae) is described. The cercaria has 47 collar spines, 2 X 15 flame cells, a small dorsal and a small ventral finfold near the tip of the tail. A peculiar organ located dorsally next to the brain is explained, hypothetically, as a statocyst. In the behaviour of the cercaria there are some conspicuous features, i.e. a rapid swimming-velocity, a striking positive geotaxis and a positive phototaxis. Second intermediate hosts are gastropods and amphibians. The metacercarial cysts exist in two distinct modifications: Cysts from Bulinus are globular, cysts from amphibians are elongated-ellipsoid. The Bulinus population of the habitat shows at the same time a high prevalence of Schistosoma haematobium. C. ogunis has never been observed as being involved in double infections. This seems to suggest that the rediae of this species are incompatible with other trematodes in the snail.