A newEuplotesmorphospecies,E. margherensisnov. spec, belonging to the group of species characterized by a dorsal silverline system of the ≪double≫ type and a set of 10 frontoventral cirri, is described. It was isolated from a sample collected in a central area of the Lagoon of Venice. It is of small dimensions, about 50 × 40 μm, and is endowed with a small projection on the right ventral front and with an indented margin which bounds the right side of the adoral zone of membranelles.