Opisthobranchiate Mollusca from Ghana: Discodorididae

Descriptions are given of eleven species of Discodorididae belonging to nine different genera collected in Ghana between 1963 and 1973; seven are described as new species while an eighth is also only known from Ghana but was described by the author over 40 years ago. The remaining three species have been recorded from Europe and east Atlantic islands, so it is probable that many of them will be found to have similar geographical ranges. The secretion of sulphuric acid by Geitodoris tema is described and evidence is presented to confirm that a characteristic of the genus Geitodoris Verrill 1880 is the presence of large acid-secreting subepidermal glands in the notum. There is no evidence at present that the superficially similar subepidermal glands of Paradoris also secrete acid. Five of the eleven species belonging to the genera Baptodoris, Jorunna and Rostanga have well-developed caryophyllidia covering the dorsal surface which give them a texture similar to that of sponges.