Kalyptorhynchia (Turbellaria) aus dem Eulitoral der deutschen Nordseeküste

Abstract

In the eulittoral beaches of the German North Sea coast 85 species of Kalyptorhynchia were found during investigations in 1966, 1967 and 1968. Studies were carried out mainly on the North Sea islands of Sylt, Amrum, Helgoland (Germany) and Rømø (Denmark). At Sylt, most species were found in more or less exposed beach slopes and in the adjacent sheltered sand flats on the east coast. 73 of the 85 species found in the North Sea are psammobiontic, 7 species prefer muddy substrata, and only 5 species live in the phytal. 29 new species are described. Many other species which were, hitherto, known only incompletely, have been studied in more detail. The Schizorhynchia are the group around which the present study centres. Eukalyptorhynchia (39 species): In the families Polycystidae, Koinocystidae, Cystiplanidae and Gnathorhynchidae new genera and species are described. Particularly notable is the addition of species to the Gnathorhynchidae, where many new combinations of characters for the proboscis have been discovered. Schizorhynchia (47 species): 6 new genera are established. The diagnosis of the Schizorhynchidae is modified. In the large genus Proschizorhynchus, 2 subgenera (P. Proschizorhynchus and P. Proschizorhynchella) are distinguished according to the structure of the male cuticular apparatus. In the new genus Neoschizorhynchus the shortest muscular tongues known to date are described. Particular emphasis is laid upon the fact that they occur in combination with specific features of the male organs. For the large genera Carcharodorhynchus and Thylacorhynchus a systematic key is given, which is founded on newly discovered combinations of morphological characters. The Karkinorhynchidae are subdivided into the new subfamilies, Karkinorhynchinae and Cheliplaninae, based on the form of the lateral proboscis gland sacs and the construction of the copulatory organ. The genus Karkinorhynchus is split into the subgenera K. Karkinorhynchus and K. Karkinorhynchoides. Further new species within the closely related genera Cheliplana and Rhinepera are described. To the Diascorhynchidae is added the new genus Diascorhynchides, which differs from the hitherto single genus Diascorhynchus by pronounced asymmetric proboscis hooks and single stilett spines. © 1970 Biologischen Anstalt Helgoland.