Atlanta tokiokai, a new heteropod (Gastropoda)

Souleyet (1852) described three species, Atlanta gibbosa, A. inclinata and A. lamanoni, which have been frequently confused. Tesch (1908) created the new genus Protatlanta for the species lamanoni which should be named souleyeti according to Smith (1888) as lamanoni was preoccupied. Tesch (1949) gives A. gibbosa as a synonym of A. inclinata. As intermediate forms between A. gibbosa and A. inclinata are frequently found, we agree with Tesch. There are, however, specimens which resemble A. gibbosa very closely but which do not show intermediates with this species. Whether Souleyet based A. gibbosa merely on specimens which now have to be considered as belonging to A. inclinata, is dubious. Tokioka (1961, fig. 35) figured such a gibbosa-like specimen but considered it as probably representing Protatlanta souleyeti, while he discussed the resemblance of his specimen with A. inclinata and A. helicinoides (Souleyet, 1852). Among material collected by the Cicar project in the Caribbean Sea the second author found a specimen closely resembling the specimen figured by Tokioka (1961) which enabled us to describe it as a new species. The name Atlanta tokiokai is proposed in honour of Dr. T. Tokioka who was the first to draw attention to this heteropod.