After the study of literature and material collected in both sides of the Atlantic Ocean, Mediterranean and Caribbean included, all the nominal species belonging to the blue chromatic group are reviewed.
From this study it is concluded that there are 17 valid species in this area, l beloning the the genus Glossodoris: G. edmundsi, 14 to the genus Hypselodoris: N. villafranca, N. tricolor, N. picta, H. orsinii, N. fontandraui, H. bilineata, N. acriba, N. bayeri, N. zebra, N. ruthae, H. marci, H. cantabrica, N. malacitana and H. pinna, 2 to the genus Mexichromis: M. francoisae and M. kempfi, and l to the genus Risbecia: R. nyalnya. For the species H. picta, H. bilineata and N. villafranca subspecies have been defined on the basis of diferences in colour pattem.
Eigth new species are described, 6 in the genus Hypselodoris: N. gasconi, N. gofasi, H. xicoi, N. ciminoi, N. muniani, and N. espinosai, 1 in the genus Chromodoris: Chromodoris goslineri, and 2 in the genus Mexichromis: M. molloi and M. garciagomezi.