This paper attempts to determine the phenetic and biogeographic relationships of species of
Ophelia. The genus is represented by 32 species, including four abranchiate species. Most of the species live on clean fine or medium sand communities in the infralittoral zone and have a restricted biogeographical distribution. The largest number of
Ophelia species (25 species) live in the Atlantic Ocean. Eight main groups are identified by the phenetic analysis. Each group is distinguished by a set of morphological characters and certain range of geographical distribution. The results allow us to advance a hypothesis that
Ophelia originated in the southern part of the Atlantic Ocean.
