The egg shells of Pseudemys scripta have two layers, one external of calcium salts and the internal of a proteic nature. The multishaped structures ("units") of the calcareous layer are bordered by groves that allow sorne expanssion when the egg becomes turgent. Those units are made of series of concentric lamellae, rich in thin or short needles. The proteic layer has two regions, the external one with fibers internall in several dirrctions; the internal layer is a thin invaginated film.
Keywords: Pseudyms, egg-shell, ultraestructure