A synopsis of the section Primigulella Pilsbry of Gulella Pfr. (Mollusca, Streptaxidae)

One of the writers (VERDCOURT, 1953) has already made some remarks concerning the members of this section which occur in the Usambara Mountains, Tanganyika. This short paper is a review of the section as a whole. The section Primigulella is the most distinct section in the genus. It has a very characteristic appearance due to the numerous teeth and lamellae and to the shape of the specialised parietal angular lamella. The anatomy of the genus as a whole is too poorly known for one to conclude that the section merits generic rank, but it is probable that it does. It would not be wise to add to the already far too numerous minor generic splits without very good evidence. There is nothing wrong with large genera and some recent splitting seems to have been done merely on the grounds that certain genera are unwieldy. CONNOLLY (1930) gave the section Conogulella PILSBRY (1919) generic rank on the evidence of the radula — the lateral teeth are bicuspid. The radula of the totally distinct Gulella usambarica (Crn.) has quadriserrate cusps on the marginals (VERDCOURT, 1953) and it would be unwise to use radula characters until a very large number of species have been examined. There are undoubtedly many distinct kinds of radulae in the genus. During the preparation of a key to the East African Gulellae, still in an embryo state, the author (BV) came to the conclusion that the only other natural groups yet named were the Microstrophia-like section Costigulella and the section Plicigulella. Mirigulella Pilsbry, 1933, Aenigmigulella Pilsbry 1933, and Thaumatogulella Haas, 1951, have been proposed for single extraordinary shaped species. The sections Molarella Connolly, 1922, and Paucidentina Martens, 1897, as at present constituted seem heterogeneous to an extreme.