Gittenedouardia conulina (von Martens, 1869)

Rowson, B, Warren, B. H. & Ngereza, C. F., 2010, Terrestrial molluscs of Pemba Island, Zanzibar, Tanzania, and its status as an " oceanic " island, ZooKeys 70, pp. 1-39 : 13

7. Gittenedouardia conulina (von Martens, 1869) Fig. 29

Buliminus (Pachnodus) von Martens 1869: 153

Notes.

The name Gittenedouardia Bank & Menkhorst, 2008 recently replaced Edouardia auctt. non Gude ( Bank and Menkhorst 2008). The slender-shelled East African species of Gittenedouardia differ subtly in shell proportions. Two of the Pemba shells are large enough to be adult, at 9.8 × 5.5mm (Fig. 29) and 8.2 × 4.1mm. These were compared with photographs of the lectotypes of Gittenedouardia conulina , Gittenedouardia metula (von Martens, 1895), and Gittenedouardia sordidula (von Martens, 1897) (all in ZMB) and Gittenedouardia tumida (Taylor, 1877) (in BMNH). Gittenedouardia conulina and Gittenedouardia metula appear to be the ends of a shape continuum from slender with less tumid whorls (conulina) to broad with tumid whorls (metula). The Pemba shells, Gittenedouardia sordidula , Gittenedouardia tumida , the other shells in the Gittenedouardia tumida type lot (see Rowson 2007, p.434), and probably Gittenedouardia metuloides (E. A. Smith, 1899) of Malawi and southern Africa, are each somewhere in the middle. A similar species is recorded from Aldabra (as Edouardia cf. tumida in Gerlach 2006b) and the Comoros Bulimus badiolus Morelet, 1881 also appears to belong to this group. This merits more detailed analysis but for now we associate the Pemba species with Gittenedouardia conulina . This happens to be both the only species previously recorded from Pemba and the oldest available name. It was noted on Pemba by Voeltzkow (1923) and Haas (1929) as Conulinus conulinus (von Martens)

Rowson (2007, p.433-434, 454-455) considered Gittenedouardia conulina one of the few taxa recorded from both Unguja and Pemba, but not the mainland. Given the tax onomic problem this is of little biogeographic significance. Regrettably the confusion in this group may have been added to by contradictorily illustrating Gittenedouardia conulina with a specimen from the mainland (Kilifi, Kenya) ( Rowson 2007: Fig. 27). This bleached specimen’s identification (by the late T. Pain) as " Cerastus conulinus (Mts.)" was taken at face value, but it is too large (16.1mm) to be either Gittenedouardia conulina or Gittenedouardia sordidula . The name sordidula was introduced by von Martens (1897) to replace the homonym conulinus von Martens, 1878 (not von Martens, 1869) after having used the name conulinus for what he later considered two separate species in the same genus. As stated above, we consider the lectotypes of these two species, conulina and sordidula to be very similar, but the drawings in von Martens (1897) rather emphasise the differences which may have helped to mislead Pain. However, whichever species the Kilifi specimen represents, it is not one recorded from Unguja or Pemba.