Studies on the Streptaxidae (Mollusca, Gastropoda Pulmonata) of Malawi 8. A revision of ‘Marconia’ hamiltoni (Smith), the largest local

‘Marconia’ hamiltoni s.l. is known from two discrete mountainous areas in Malawi, i.e. the (southern) Mt. Mulanje complex, and the (more northern) Zomba Plateau s.l. These uplands are separated by about 65 km of lower lying land with different types of vegetation and climate. Material from these two regions may be distinguished as separate species, the southern populations having comparatively small and broad shells with some apertural dentition (‘M’. hamiltoni, lectotype designated), while the northern populations have noticeably larger and more slender shells with a more reduced apertural dentition (‘M’. malavensis). Discussion of the type localities for both taxa shows that these are either localized in an unlikely place (‘M’. hamiltoni) or unclear (‘M’. malavensis). Radula and genital anatomy of ‘M’. hamiltoni are described and depicted for the first time. Both species are ovoviviparous, a rarely reported phenomenon in the Streptaxidae. The genitalia are markedly different from what is known in various streptaxid genera with which these species may be or have been classified. In spite of the confused streptaxid taxonomy, a new genus, Austromarconia, is introduced with Ennea hamiltoni as type species.