Abstract
Schizoporella ansata (Johnston, 1847) is synonymous with S. unicornis (Johnston in Wood, 1844), which is characteristically a littoral species in western Europe. Specimens collected offshore, differing most notably from S. unicornis in the shape of the poster (sinus) of the orifice, constitute the S. ansata of authors. The sub-littoral species with a D-shaped anter to the orifice, which occurs off Atlantic coasts of Europe, is recognized as S. dunkeri (Reuss, 1848), a Tertiary species which had also been referred to S. ansata. The Mediterranean offshore form, however, with an orbicular anter to the orifice, represents S. magnifica Hincks (1886). It is here recorded from southern Britain. Shorter mention is made of S. errata (Waters, 1878), which has been confused with S. unicornis, from which it differs most notably in the shape of the sinus. The Tertiary species S. tetragona (Reuss, 1848), which has been confused with both S. dunkeri and S. errata, is described and distinguished from these species. It is here recognized for the first time as a Recent species.

This publication has 8 references indexed in Scilit: