New species of land snails (Mollusca: Gastropoda) from two isolated karst formations in central western Madagascar: Tsingy Beanka and Antsingimavo, with additional notes on other regional endemics Author Griffiths, O. L. Research associate of the Australian Museum, Sydney, Australia and Biodiversity Conservation Madagascar (BCM) Ltd, Rivière des Anguilles, Mauritius owen@bcm.intnet.mu Author Herbert, D. G. KwaZulu-Natal Museum, P. Bag 9070, Pietermaritzburg, 3200 South Africa and School of Life Sciences, University of KwaZulu-Natal, Pietermaritzburg, 3206 South Africa dherbert@nmsa.org.za text African Invertebrates 2013 2013-02-13 54 1 1 48 journal article 54828 10.5733/afin.054.0101 753510a6-cffa-4637-a1bd-e9ae7d5d1660 2305-2562 7670100 3795B466-1227-4BED-AD8A-DC88CA3E14E1 Acroptychia bathiei Fischer-Piette & Bedoucha, 1965 Figs 2 , 3 , 25A Acroptychia bathiei : Fischer-Piette & Bedoucha 1965: 61 , fig. 12, pl. 1, figs 9–11; Fischer-Piette et al . 1993: 47, pl. 1, figs 19–21. Type loc.: ‘près de la rivière Andranomavo (Ambongo)’ [Perrier de la Bâthie leg.], NW Madagascar’. Morphological notes: External features ( Fig. 25A ): Head-foot mostly greyish, irregularly mottled with darker spots and blotches; eyestalks pale, but tentacles more or less uniformly dark; forehead and snout brown; tip of snout shallowly indented in mid-line; skin texture relatively smooth. Operculum : Corneous, oligospiral with an eccentric nucleus. Radula ( Fig. 3 ): Formula 1+2+1+2+1; length 12 mm , with ca 140 tooth rows [ ca 11.5 rows/mm]; teeth robust. Rachidian tricuspid with a rounded central cusp and two smaller lateral ones; inner and outer laterals similar, each with four cusps, of which the second is consistently the largest; marginals bicuspid, the outer cusp larger. Very similar to that of A. culminans Fischer-Piette & Bedoucha, 1965 , as described and illustrated by FisherPiette et al . (1969) , except that the outer lateral is mostly tricuspid in that species. Fig. 2. Acroptychia bathiei Fischer-Piette & Bedoucha, 1965 : (A–C) Tsingy Beanka , st’n 18/06, max. diameter 23.7 mm, NMSA L7174; (D–F) Antsingimavo, st’n 04/06, NMSA L7091: (D) typical shell, max. diameter 23.0; (E) pale yellow specimen with a less elevated spire, max. diameter 21.7 mm; (F) juvenile specimen, max. diameter 14.9 mm. Fig. 3. Acroptychia bathiei Fischer-Piette & Bedoucha, 1965 , radula, NMSA L7039: (A) entire width of radula; (B) oblique view of left half row. Scale bars = 100 μm. Locality data: Namoroka : st’ns 930/97, 932/97. Antsingimavo : st’ns 04/06, 06/06, 08/06. Tsingy Beanka : st’ns 03/06, 11/06–13/06, 16/06–18/06, 01/09, 02/09, 06/09–09/09, 11/09, 01/10, 03/10, 05/10–08/10, 10/10. Tsingy de Bemaraha : st’ns 07/95, 14/95, 18/95, 09/96, 10/96, 12/96, 14/96. South bank of Tsiribihina R. : st’n 02/99LP. Distribution: Restricted to central W Madagascar ; from the Tsiribihina R. and southern Bemaraha region through Tsingy Beanka and Antsingimavo to the Namoroka area. Habitat: Dry mixed deciduous-evergreen forest growing on limestone; living in leaflitter, under limestone rocks and in soil pockets on karst boulders; patchily common at both Tsingy Beanka and Antsingimavo. Also common throughout most of the Tsingy de Bemaraha reserve. Remarks: A moderately sized, thick-shelled species with a single, well-developed, terminal, peristomal varix. Diameter rarely more than 24 mm . Shell essentially smooth save for fine axial pliculae on the early teleoconch whorls and fine, close-set growth-lines on later whorls. Umbilicus relatively narrow and deep. Juveniles have a much thinner shell that is frequently weakly angled at the periphery ( Fig. 2F ). The ground colour ranges from a pale yellowish white to a deeper pinkish or orangebrown; in fresh specimens this is overlain by a fine, irregular whitish mottling, which is in turn overlain by a thin, rather glossy, corneous periostracum. However, the latter is commonly eroded in parts, after which the whitish mottling is quickly worn off and the shell becomes more uniformly coloured. A darker spiral line is frequently present just below the periphery, occasionally another just above it and sometimes a third in the middle of the base. Family Pomatiidae Newton, 1891 Genus Tropidophora Troschel, 1847 Tropidophora chavani Fischer-Piette, 1949 Figs 4 , 9E Tropidophora chavani : Fischer-Piette 1949: 15 , pl. 1, figs 4–6; Fischer-Piette & Bedoucha 1965: 73; FischerPiette et al . 1993: 102 , pl. 5, figs 6–8. Type loc.: ‘gorges de Salapanga (Bemaraka)’ [= Bemaraha]. Fig. 4. Tropidophora chavani Fischer-Piette, 1949 : Tsingy Beanka , st’n 15/06, max. diameter 27.0 mm, NMSA L7129. Locality data: Tsingy Beanka : st’ns 12/06, 14/06, 15/06, 01/09, 02/09, 06/09, 07/09, 08/09, 09/09, 01/10, 05/10, 07/10, 08/10, 09/10, 10/10. Tsingy de Bemaraha : st’ns 18/95, 04/96, 09/96, 10/96, 12/96. Distribution: A narrow-range endemic; currently recorded only from the Bemaraha region and Tsingy Beanka . Habitat: Dry forest growing on limestone; found in leaf-litter and between limestone boulders. Remarks:A moderately common species in the central Tsingy Beanka , but usually present at rather low density. It is characterised by its low spire and uniformly fine spiral sculpture. Specimens with a similarly dense spiral sculpture have been collected at Andranavory in the Toliara [Tuléar] region, but these are more elevated and have a flaring white lip, which is broadly reflected in the columella region, half covering the umbilicus. They are closer to T. semidecussata (Pfeiffer, 1847) than they are to T. chavani .