1- The present Investigation deals with the description of the shell, operculum and
soft parts of one of our local freshwater operculate snails, known as Bellamya
unicolor (OLIVIER, 1801). Such study has not been carried out before. 2. The characters of the shell and operculum do not show clearly that the snail be
longs to genus Bellamya as reported by MALEK and CHENG (1974, p. 69). But accor ding to ROHRBACH (1937) and MANDAHL-BARTH (1954) the position and shape of the testis in the male and the shape of the receptaculum seminis in the female of the
present species show that it can be put under the genus Bellamya. 3- The present species has the characteristic viviparid ciliated groove on the floor
of the mantle cavity and leading to the mouth opening via the cephalic groove below the right tentacle. It has also the terminally free filamentous gills which together with mucous, aid in the collection of food particles. During life, there is an inhalent left siphon and an exhalent right one at the mantle edge, causing a continuous current of water within the mantle cavity. Therefore, the snail is adapted for ciliary feeding.