ORGANIZATION OF THE EPIDERMAL SYNCYTIAL MOSAIC IN DICERATOCEPHALA-BOSCHMAI (TEMNOCEPHALIDA, PLATYHELMINTHES)

The epidermis of Diceratocephala boschmai Baer, 1952 (Temnocephalida : Platyhelminthes) was studied using silver-nitrate staining and electr on microscopy. The epidermis consists of six syncytia separated by lat eral membranes: the frontal, trunk, stalk, adhesive disc syncytia, and a pair of post-tentacular syncytia. Neighbouring syncytia differ in m any characters including (1) the presence or absence of locomotory cil ia, (2) the degree of the differentiation of the apical cytoplasm laye r, (3) the presence or absence of bundles of cytoskeletal filaments, i maginations of basal membrane and other specialised cytoplasmatic stru ctures, (4) the abundance of hemidesmosomes at the basal membrane, and (5) the abundance and nature of gland ducts penetrating the syncytium . These structural differences reflect functional differences between the syncytia. Thus, multisyncytial organisation of the epidermis may b e explained by functional differences between the syncytia. Only betwe en the frontal and trunk syncytia has no apparent ultrastructural diff erence been found.