[Operculated eggs of Platyhelminths: description of atypias and attempted explanation of their genesis].

The authors remind the formation of operculated eggs. Atypical eggs of Clonorchis sinensis, Fasciola hepatica and Diphyllobothrium latum are described: no operculum for the two first species and existence of non-described buttons for the two last species. These anomalies could be explained by the way of formation of these eggs.