NEW SPECIES OF EUGLESIDAE (BIVALVIA, PISIDIOIDEA) FROM THE DNIEPER DRAINAGE AREA

The new subgenus Potamopisidium with 2 species is described in the genus Cingulipisidium Pirogov et Starobogatov, 1974. Patterns of its mantle musculature are intermediate between those of Cingulipisidium (Hiberneuglesa) and Cingulipisidium s. str. An advanced character of ctenidium, i.e. considerable reduction of outer demibranch distinguishes the new taxon within the genus. Close phylogenetic relationship between Potamopisidium and Conventus is proposed. The new species Euglesa (Cyclocalyx) latiumbonata Korniushin, sp. n. shares some similarities with E. (Roseana) which presumably is ancestral for Cyclocalyx subgenus. Other 2 new species of different genera are found in the collections from western Europe stored in Zoological Museum in Leningrad: Euglesa (E.) platyponderosa Starobogatov et Korniushin, sp. n., E. (Roseana) silesiaca Star. et Korn., sp. n. All of them have specific shape of frontal section of the valve. C. (C.) feroense Morch in coll. is redescribed.