| <i>Tisbe furcata, T. gracilis, T. holothuriae</i> and <i>T. battagliai</i> are reported from the Sluice Dock near Ostend (Flemish Coast). The latter three species are new to the Belgian fauna. A cross-breeding experiment between strains of <i>T. holothuriae</i> from Ostend and Venice (Italy) conforms perfect interfertility and hybrid F<sub>1</sub> heterosis. <i>T. furcata</i>, the "stumbling block" of the genus, is described and an account is presented of the characteristics and ontogeny of its colour pattern. |
