COMPARATIVE-MORPHOLOGICAL ANALYSIS OF THE ORGANIZATION OF CEPHALORHYNCH WORMS, THE PHYLOGENY AND SYSTEM OF THE PHYLUM CEPHALORHYNCHA .4. EXCRETORY ORGANS, REPRODUCTIVE-SYSTEM AND DEVELOPMENT, PLESIOMORPHY AND APOMORPHY IN THE SERIES OF CHARACTERS

In priapulids and loriciferans, the excretory and genital systems are combined into the urogenital system, which is considered as plesiomorp hous character within Cephalorhyncha. Kinorhynchs are characterized by separated excretory and reproductive systems. Cephalorhynchs are char acterized by radial (or non-spiral) cleavage, deuterostomity, and the presence of a septum separating the introvert from abdomen in embryos and early postembryonic stages. The series of pleisomorphic and apomor phic conditions of the most important morphological characters in ceph alorhynchs are demonstrated.