Abstract
This is the fifth publication describing species of sea slug heterobranchs, originally based on collections from the Red Sea by the author on four expeditions carried out in 1983 and 1990, with the addition of specimens subsequently collected by underwater photographers who were stimulated by the book "Sea Slugs of the Red Sea". So much material has been amassed that only the new species and new Red Sea records of chromodorids are described in this paper, with an appendix listing specimens of previously recorded species. Three new species are described in detail and illustrated, belonging to three different genera: Doriprismatica kyanomarginatasp. n., Glossodoris kahlbrockisp. n., and Goniobranchus pseudodecorussp. n. One western Pacific species is recorded for the first time in the Red Sea, Goniobranchus collingwoodi (Rudman, 1987). The nomenclature of Verconia sudanica is discussed and stabilised.