TWO NEW SPECIES OF GASTROPTERON (GASTROPODA : OPISTHOBRANCHIA) FROM SOUTHERN AFRICA

With Text-:figures 1-10, Table 1 and Plate I The Gastropteridae are a small family of cephalaspidean opisthobranch gastropods, consisting of 19 described species in three genera.The external morphology varies considerably between species and serves as the major basis for the separation of specific taxa.Little is known about the internal anatomy of most taxa, with the exception of the radular morphology.Differences in shape and number of radular plates provide the major basis for the separation of genera.All described species have been recorded from the northern hemisphere.The only record from the southern hemisphere is that of Barnard (1963).He recorded an undescribed species from deep water off the Cape Peninsula of South Africa.The only other record of the family from the African continent is that of Gastropteron rubrum manx from off the coast of Nigeria, in the Gulf of Guinea (Marcus & Marcus, 1966).In the course of studying the opisthobranch fauna of southern Africa, living representatives of two undescribed species of Gastropteron were collected from the Atlantic coast of the Cape Peninsula, in the vicinity of Cape Town, South Africa.It is the intent of this paper to describe these species and to discuss their systematic position within the family.Comparative material of described taxa was examined to confirm some of the previous morphological studies and to provide more detailed descriptions of some taxa.It was possible to examine a syntype specimen of Gastropteron cinereum Dall, 1925.Its morphology is more completely described and its taxonomic status is revised.a -ampulla be -bursa copulatrix bg -buccal ganglion c -cerebral ganglion cr -crop