Larval stages of digenetic trematodes of Pirenella conica from Deversoir Ismailia, Egypt.

Two cercariae are described from the prosobranch snail Pirenella conica collected from Deversoir marine-water, Ismailia, Egypt. One of the ercariae is prepleuro-lophoercous group, belonging to genus Stictodora, while the second is a Ephemera monostome cercaria. The latter is a new record for Pirenella conica snail in marine water from Ismailia. Details are present on the morphology and behavior of the cercariae and rediae, as well as of their development within the snail, with discussion and comparison of previously described cercariae. The incidence of single (pure) and simultaneous mixed (double) infection of snail with two larval trematodes were also determined.