The sizes of the Black Sea ctenophore <i>Pleurobrachia</i> correspond to species <i>Pleurobrachia pileus</i> (O. F. Müller, 1776)
It has been shown that a mistake in determination of the definitive sizes of ctenophore Pleurobrachia, inhabiting the Black sea led to a wrong name of species in “Guide of the fauna…” (1968).