Planktotrophic Columbellidae (Gastropoda) in the northeast Atlantic and the Mediterranean Sea, with description of a new species in the genus Mitrella

Very few of the ca 50 species of Columbellidae found in the Eastern Atlantic Ocean have planktotrophic larval development denoted by a multispiral protoconch. One species of the genus Mitrella , ranging from the mid-Atlantic seamounts to the Alboran Sea, is here described as new to science and the geographic and bathymetric distributions of another three species, Amphissa acutecostata (Philippi, 1844), Mitrella canariensis (d’Orbigny, 1840) and M. nitidulina (Locard, 1897) are updated. The name Mitrella canariensis is shown to have precedence over M. pallaryi (Dautzenberg, 1927). Mitrella nitidulina is absent in the Mediterranean Sea, and A. acutecostata , the only amphiatlantic species, is recorded for the first time as living in the Alboran sea. There is a definite differentiation in the bathymetrical range of these species, with M. canariensis the shallowest and M. nitidulina (Locard, 1897) the deepest