[Ultrastructure of the cyst wall of Aploparakis polystictae and A. furcigera (Cestoda, Cyclophyllidaea) metacestodes].

The development of the additional membrane (exocyst) from the caudal appendage in diplocysts does not change essentially the structure of the cyst's wall in metacestodes of the genus Aploparaksis. In cytoplasmic connections between cytons and the surface syncytium there are two autonomous enough systems of transport: microtubes opening to the surface of tegument and matrix of bridges which proceed to the matrix of external syncytium. In addition to cytons, in the cyst's wall there are cells with an enlarged granulated endoplasmic network, which are miofibroblasts, secretory cells performing an unclear function, protonephridia and cells limiting the cavity of the cyst of the layer. Differences in the larval morphology of both species are quite negligible and can be due to their age peculiarities.