New taxa of Streptaxidae and Enidae (Mollusca, Gastropoda Pulmonata) from South Africa and Malawi

For various reasons a number of discoveries in the field of Southern African malacology has now reached a point where there is no need for further delay in publication. In the course of a long term project, the revision of the Streptaxidae of Southern Africa, three new taxa have come to light which are described below. Mr. C. C. Appleton (Bilharzia Research Unit, Nelspruit, South Africa) during an extended period of research in Tongaland (NE. Zululand, South Africa) has found a remarkable new form of the genus Gulella L. Pfeiffer, 1856. This is seemingly closely related to a recently described extinct species from Aldabra Island in the western Indian Ocean (Van Bruggen, 1975). It is an unfortunate consequence of the rules of zoological nomenclature that the extinct form on Aldabra, G. p. peakei Van Bruggen, 1975, is the nominate subspecies, while the extant, continental form, G. p. continentalis n. subsp., undoubtedly the ancestor of the island subspecies, now has to be described as a subspecies of the island form instead of the other way round. It is convenient to add the description of two new species of Gulella as it is unlikely that further material of these will be forthcoming in the near future. One of the species was already discovered in the Transvaal in 1966 by the present author, but the availability of only two specimens of this otherwise quite distinct species was the reason for delay here. The second species is another discovery in Tongaland by Mr. Appleton and, although founded on a singleton, was deemed sufficiently characteristic to warrant description. This has become necessary in view of the preparation of a forthcoming joint paper with Mr. Appleton on the terrestrial molluscs of