On a collection of Opisthobranchia from Turkey

This paper deals with the Opisthobranchia collected by the Netherlands Biological Expedition to Turkey 1959. The collection is deposited in the Rijksmuseum van Natuurlijke Historie at Leiden. The material was chiefly collected in three areas, viz. the Bay of Antalya and the Bay of Mersin (formerly Içel), both in the Eastern Mediterranean on the south coast of Turkey, and the environs of Trabzon on the southeast coast of the Black Sea. The collection is rather small, comprising 25 species, which is probably only a fraction of the total Opisthobranchiate fauna of Turkey. Of course most of these species have also been recorded from the much better known Western Mediterranean. All the same, examination of the collection yielded some surprising facts. To my knowledge the species Cyerce jheringi and Discodoris maculosa had so far only been found near Naples. Up to now species of the genera Chelidonura, Bursatella and Taringa had not been recorded from the Mediterranean. Three species could not be identified with known species and are here described as new. LIST OF THE SPECIES Order Cephalaspidea Family Bullidae. 1. Bulla striata Bruguière, 1792. Family Gastropteridae. 2. Gastropteron rubrum (Rafinesque, 1814). Family Aglajidae. 3. Chelidonura mediterranea spec. nov. Family Philinidae. 4. Philine aperta Linné, 1767. Family Atyidae. 5. Haminea hydatis (Linné, 1758). Family Retusidae. 6. Retusa semisulcata (Philippi, 1836). 7. Retusa mammillata (Philippi, 1836).