ИСТИНА

Summary. The study found that the attachment organ of adult C. truncatus is false sucker, formed as a result of proliferation of the body wall, which has specialized muscles with typical ultrastructural features of the building. In the study of the ultrastructure of the excretory system have been found new, previously unknown features of the organization oder Spatebotriidea : channel walls are formed by epithelial-muscle cells, and the terminal cells may contain two ciliate complex located in perpendicular planes. These features of the organization, taking into account the reticular structure of the plan, refer to the archaic, peculiar to the hypothetical ancestor of flatworms. The study of the microscopic anatomy of the nervous system greatly clarified the data obtained by previous authors, and showed the presence of 4 major neuropil in the basis of false sucker, connected by 2 pairs of dorsal and ventral commissures. Synaptic apparatus is described, which showed a high degree of development.