Species complex 4: “ similis ”

A set of Mediterranean and Atlantic specimens with a common range of morphological traits constitutes a species complex displaying a remarkable example of a morphological cline. Three geographically separated morphotypes, differing mainly in the structure of their orifice, are considered to be different species, two of which being new to science. The orifice structure of these species poses the fundamental question of the boundary between the genera Escharella and Hemicyclopora .