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. 25 A) : 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. culminons Fischer-Piette & Bedoucha, 1965, as described and illustrated by Fisher-Piette et al. (1969), except that the outer lateral is mostly tricuspid in that species.

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'n02/99LP.

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 leaf-litter, 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.

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].

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.

Etymology: The colour pattern of bold stripes is reminiscent of that of old-fashioned humbug sweets; used as a noun in apposition.

Diagnosis: Spire very low, shell almost planorboid, body whorl not conspicuously tumescent, umbilicus very wide; columella lip not expanded and not reflected over umbilicus; surface virtually smooth to the naked eye; boldly marked with brown spiral bands on a near white ground.

Description:

Shell: Medium sized, depressed-discoidal to planorboid; spire very low (H : D=0.46– 0.62), often with only embryonic whorls projecting in apertural view; final part of last adult whorl descending prior to aperture, but not steeply so; whorls more or less evenly rounded, suture indented; umbilicus very wide, its margin evenly rounded, underside of embryonic whorls clearly visible. Protoconch of 1¼–1½ whorls, essentially smooth, but microscopically shagreened. Teleoconch of a further 2½–2¾ whorls; the first with approx. 6 weak spiral ridges crossed by numerous fine, close-set, axial threads; spirals becoming more numerous but less distinct on subsequent whorls and axials somewhat coarser; axials resembling fine, uneven, close-set growth-lines on last half-whorl of adult, these extending onto base and into umbilicus; base lacking spiral sculpture. Aperture subcircular, strongly oblique to vertical axis of shell; peristome incomplete, interrupted briefly in parietal region; rim of peristome reflected forming a flaring lip, but this not noticeably enlarged in columella region.

Ground colour bone-white, boldly marked with dark brown spiral bands, the one at and extending just below periphery usually broadest, commonly with 2 or 3 additional bands above and a further 2 or 3 below this; an additional fine orange-brown intermediary spiral line sometimes present in intervals between bands; umbilical region with additional colour bands, often fine, such that base may have up to 7 bands in total; exceptionally, base may have only 1 or 2 colour bands; precise position of colour bands somewhat variable, but uppermost band generally not in contact with suture.

Dimensions: Holotype, max. diameter 31.5 mm, height 16.3 mm; largest specimen, max. diameter 32.0 mm.

External features (Fig. 25B): Head-foot more or less uniformly dark grey-brown, but eyestalks and tentacle bases paler; tip of snout conspicuously indented in mid-line; skin texture finely granular.

Operculum (Fig. 5G): Oligospiral; exterior portion a calcareous disc, attached to an inner and slightly larger corneous layer; external surface off-white (usually encrusted with detritus particles), lacking colour pattern, but with a broad convex spiral ridge more or less at mid-whorl; thinner toward periphery; edge of disc concave, with numerous, closeset, rather unevenly spaced transverse partitions, except along the growing (parietal) margin, which is smooth.

Radula (Fig. 6): Formula 1+2+1+2+1; length 11 mm, ca 35 rows/mm; dentition fine. Rachidian with seven rounded cusps, central one largest, the outermost pair small; occasionally with very small intermediary teeth between the larger ones. Inner laterals with four cusps, the second of which is bluntly rounded and consistently the largest, the others more pointed; outer lateral with five cusps, the inner one usually slightly larger, the others progressively smaller. Marginal teeth broad, the edge comprising three regions; an inner coarsely dentate element with ca 9 denticles; a more finely denticulate central region, and a smooth outer portion. Such a radula conforms to the pattern seen in Tropidophora (Ligatella) Martens, 1880 (Fischer-Piette et al. 1969).

Holotype: MADAGASCAR: Central W Madagascar, ca 60 km E of Maintirano, tall dense dry forest growing above cliffs on E side of southern Tsingy Beanka at Andohanandranogedro, 18.05028°S 44.53786°E, 380 m, iv.2009, R. Randalana, st'n R04/09 (AMS C.474165).

Paratypes: Same data as holotype (NMSA L8547/T2962, 2 specimens); st'n 14/95 (AMS C.469588, 5 specimens); st'n 10/96 (AMS C.469587, 5 specimens); st'n 14/96 (AMS C.469589, 2 specimens); st'n 15/96 (NMSA L8444/T2658, 6 specimens); st'n 03/06 (NMSA L7042/T2961, 45 specimens, some in alcohol; MNHN IM-2010-20067,2 specimens; NHMUK 20120013,2 specimens); st'n 12/06 (NMSAL7204/T2984, 2 specimens); st'n R04/09 (AMS C.469590, 6 specimens; TMAM T166, 7 specimens); st'n R01/10 (TMAM T160, 5 specimens); st'n R02/10 (MNHN IM-2010-20068, 7 specimens).

Additional locality data: Tsingy Beanka: st'ns 05/06, 11/06, 12/06, 13/06, 16/06, 18/06, 01/09, 03/09, 11/09, 03/10, 10/10. Tsingy de Bemaraha: st'ns 08/96, 09/96.

Distribution: A narrow-range endemic; known only from the Tsingy Beanka and Tsingy de Bemaraha, but common at both these localities.

Habitat: Tall semi-deciduous and deciduous western dry forest. Often found on tree trunks after rain. Aestivates in leaf-litter.

Remarks: Fischer-Piette et al. (1993) grouped medium-sized, low-spired Madagascan Tropidophora species together in their ‘groupe d'espèces du T. deshayesiana (Petit de la Saussaye, 1844)’, but with the exception of T. vittata (Sowerby, 1843) all members of this group have much stronger spiral sculpture than T. humbug, including T. chavani Fischer-Piette, 1949 (see above) with which it is sympatric. Besides being relatively smooth, T. vittata, which is recorded only from north-eastern Madagascar (Fischer-Piette et al. 1993), shares with T. humbug a similarly banded colour pattern and is undoubtedly the most similar species. However, T. vittata has a far more prominent spire, deeper body whorl, narrower umbilicus, and a more extensively flared aperture lip, often with a wide extension in the columella region that partially obscures the umbilicus at full maturity. Fischer-Piette et al. (1993) stated that the holotype of T. vittata was in the NHMUK, but it could not be located there (Ablett in litt. Nov. 2011). T. semidecussata (Pfeiffer, 1847), is also similar and though a very variable species, like T. vittata, it has a more elevated spire, tumescent body whorl, narrower umbilicus and a more well developed, strongly reflected columella lip.

Specimens of T. humbug from the Tsingy de Bemaraha commonly have a slightly more elevated spire than those from Tsingy Beanka, but H : D ratios for the two populations overlap considerably (H:D=0.47–0.61 compared to 0.46–0.53 respectively).

Cyclostoma reticulatum: Reeve 1861: pl. 9, fig. 48a, b [non Adams & Reeve 1850 in 1848–1850: 57, pl. 14, fig. 8].

Tropidophora reticulata: Fischer-Piette 1949: 36.

Tropidophora secunda: Fischer-Piette & Bedoucha 1965: 76. Type loc: Madagascar.

Tropidophora (Ligatella) secunda: Fischer-Piette et al. 1993: 129, fig. 82.

Morphological notes:

External features (Fig. 25C): Head-foot more or less uniformly grey; tentacles and forehead slightly darker, paler toward mantle cavity; tip of snout conspicuously indented in mid-line; skin texture very finely granular.

Operculum: Oligospiral; exterior portion a calcareous disc, attached to an inner and slightly larger corneous layer; external surface very shallowly concave, lacking a distinct convex spiral ridge (cf. T. humbug above), but with a diffuse, dark purple-brown spiral band more or less at mid-whorl, most noticeable on last whorl; edge of disc concave, with relatively weakly developed transverse partitions (adjacent to inner surface), except along smooth growing margin.

Radula (Fig. 8): Formula 1+2+1+2+1; length 7.3 mm, ca 42 rows/mm; dentition fine. Rachidian with five distinct cusps, a minute additional pair sometimes discernable; central cusp largest and rounded, the outer pair small and curving inward. Inner laterals with four cusps, the inner cusp small and often obscured by the much larger second cusp; outer lateral with five or six cusps, the central three or four usually larger. Marginal teeth broad, the edge comprising three regions; an inner coarsely dentate element with ca 9 denticles; a more finely denticulate central region, and a smooth outer portion. Such a radula conforms to the pattern seen in Tropidophora (Ligatella) Martens, 1880 (Fischer-Piette et al. 1969).

Locality data: Tsingy Beanka: st'ns 03/06, 11/06, 12/06, 13/06, 14/06, 15/06, 17/06, 18/06, 02/09, 11/09, R01/10, 03/10, 09/10. Kelifely Plateau: st'ns 04/05, 10/05. Anjajavy (Narinda north): st'ns 33/03, 36/03. 37/03, 38/03, 39/03, 40/03, 13/04 [abundant in this area]. Mtn d'Ambre/Ankarana: st'ns 12b/94, 01/01, 09/01 [uncommon].

Distribution: Central western to north-eastern Madagascar; from the southern Bemaraha region (Fischer-Piette et al. 1993) through Tsingy Beanka, the Kelifely Plateau and Anjajavy area, to Mtn d'Ambre and Ankarana in Antsiranana Province. Curiously, we have not found this species in our own surveys in the Tsingy de Bemaraha, nor at Antsingimavo, and whereas it is common in the southern Tsingy Beanka, it is rare in the central portion. Evidently although relatively widespread, the species has a somewhat patchy distribution within its range.

Habitat: Dry deciduous, evergreen and riverine forest in limestone areas; in leaf-litter and sheltering microhabitats amongst rocks.

Remarks: A characteristic species on account of its bold colour pattern. T. reticulata (Adams & Reeve, 1850), with which it was at one time confused, has a similar coloration, but is smaller (max. diameter approx. 16 mm, compared to >18.5 mm in T. secunda), has a more elevated shell and a narrower umbilicus (Fischer-Piette 1949) (Fig. 26G–I, syntype, NHMUK). The white markings of T. secunda are not part of the shell fabric, but are a superficial chalky deposit which can be easily scraped off. Although previously reported from few localities, the range of T. secunda is evidently relatively large and it is not uncommon in undisturbed dry forest habitat. In contrast, the range of T. reticulata has yet to be established more precisely than ‘Madagascar’. Most specimens from Tsingy Beanka have a lower spire than the holotype (compare Figs 7A and 7F); however, shells of intermediate height are present both in the Tsingy Beanka and Kelifely Plateau (Fig. 5D, E).

Fischer-Piette and Bedoucha (1965) selected as the ‘type’ for this species the specimen illustrated as Cyclostoma reticulatum by Reeve (1861: pl. 9, fig. 48a, b, ‘Mus. Cuming’), which they stated was present in the ‘British Museum’ [NHMUK]. Fischer-Piette (1949) had earlier examined this specimen, citing its diameter as 22 mm. No specimen identified as the holotype of Tropidophora secunda was present in the NHMUK, but a specimen labelled Cyclostoma reticulatum is present in the Cuming collection (Ablett pers. comm. Nov. 2011). This is 22 mm in diameter and closely resembles the figure given by Reeve (1861), though the colour pattern is not a perfect match. It seems very probable that this is the specimen referred to by Fischer-Piette and Bedoucha (1965), and we consider it to be the holotype ofTropidophora secunda (NHMUK 20110470, Fig. 7F–H). It is not clear why Fischer-Piette, after having examined the Cuming specimen illustrated by Reeve (1861) and designated it to be the type, subsequently stated for T. secunda ‘localisation du type: ?’ (Fischer-Piette et al. 1993).

Etymology: From Latin sericeus (silky); in reference to the silky texture of the shell. Diagnosis : Spire very low, shell almost planorboid, body whorl not conspicuously tumescent, umbilicus very wide; columella lip weakly reflected, but not broadly expanded over umbilicus; sculpture finely decussate, comprising low, close-set spiral ridges crossed by similar axial pliculae; yellowish white with traces of fine orange-brown spiral lines.

Description:

Shell: Medium to large, depressed-discoidal to planorboid, spire very low with little other than embryonic whorls projecting in apertural view; final part of last adult whorl descending gently prior to aperture; whorls more or less evenly rounded, suture indented; umbilicus very wide, its margin evenly rounded; underside of embryonic whorls clearly visible. Protoconch of 1¼–1½whorls, essentially smooth, but microscopically shagreened. Teleoconch of a further 2¾–3 whorls; first whorl initially with 6 or 7 low spiral ridges increasing to double this by end of whorl; ridges crossed by numerous, close-set axial pliculae producing a finely decussate sculpture; intervals between ridges 2–3 times wider than those between pliculae; subsequent whorls with additional spiral ridges arising by intercalation, but sculpture remaining finely decussate more or less throughout, including base; spiral ridges more close-set on later whorls and sculptural interstices less axially elongate; ridges with minute granules where crossed by axial pliculae. Aperture subcircular, strongly oblique to vertical axis of shell; peristome virtually complete, somewhat angled in parietal region; aperture expanding slightly prior to lip and lip also weakly reflected.

Ground colour dirty white to yellowish buff; the freshest specimens retaining evidence of a pattern of fine orange-brown spiral lines above the periphery, that at periphery strongest; similar lines just below periphery but umbilicus and most of base lacking colour pattern.

Dimensions: Holotype, max. diameter 37.3 mm, height 18.9 mm; largest specimen, max. diameter 41.4 mm.

Holotype: MADAGASCAR: Central W Madagascar, ca 60 km E of Maintirano, NE of Belitsaka, central part of Tsingy Beanka, in slots and small caves above Bokarano R. gorge, next to low dry deciduous forest, 17.90517°S 44.48240°E, ca 215 m, 22.ix.2010, O. Griffiths & R. Randalana, st'n 09/10 (AMS C.474166).

Paratypes: Same data as holotype (NMSAL8524/T2979, 3 specimens); st'n 06/09 (AMS C.469585, 3 adult specimens); st'n 07/09 (TMAM T161, 1 adult specimen); st'n 08/09 (AMS C.469586, 9 adult specimens); st'n 08/10 (MHNP IM-2010-20083, 4 adult specimens).

Additional locality data: Tsingy Beanka: st'ns 06/10, 07/10, 09/12.

Distribution: A narrow-range endemic; currently known only from the central region of the Tsingy Beanka.

Habitat: Found only in subfossil form in deep slots and crevices within the tsingy, in dry deciduous forest.

Remarks: Like T. humbug, this species is referable to the ‘groupe d'espèces du T. deshayesiana (Petit de la Saussaye, 1844)’ of Fischer-Piette et al. (1993). Within this group, it is closest to T. chavani Fischer-Piette, 1949 (see above) in having a very low spire, relatively fine spiral sculpture and a colour pattern of narrow, brownish, spiral bands. It is, however, considerably larger than T. chavani, attaining as much as 41.4 mm in max. diameter (compared to 32 mm for T. chavani). Furthermore, its sculpture is considerably finer than that of T. chavani, with subequal spiral and axial elements. In T. chavani the axial pliculae are crisp, and much finer and more close-set than the spiral cords (compare Figs 9D and 9E). At some localities, T. chavani occurs in subfossil form together with T. sericea, but the two remain clearly distinct.

T. moulinsii (Grateloup, 1840) (Fig. 26A–C, holotype, NHMUK) and T. thesauri Fischer-Piette, 1949 (Fig. 26D–F), both from the north-eastern tip of Madagascar, are of a more similar size (attaining 38 mm or more in max. diameter), but T. thesauri has much deeper whorls, a higher spire, narrower umbilicus, irregular scale-like subsutural pliculae and lacks the finely decussate microsculpture of T. sericea. T. moulinsii has stronger, cord-like, spiral sculpture, more tumescent whorls and a higher spire.

Etymology : Named for Roger Randalana, on-site manager of the Tsingy Beanka reserve and participant in many malacological expeditions throughout Madagascar.

Diagnosis: Shell bulimiform, whorls relatively elongate, body whorl comprising approx. 66 % of total shell height; spire profile cyrtoconoid; columella reflected, umbilicus narrow; sculptured by microscopic axial riblets and even finer spiral threads; lustreless, mauve-brown, paler apically.

Description:

Shell: Elongate-bulimiform, thin; body whorl comprising approx. 66% of total shell height; spire profile cyrtoconoid, suture not strongly indented; whorls weakly convex, base a little more strongly so, periphery rounded; umbilicus reduced to a narrow tube-like channel by reflected upper portion of columella lip. Protoconch of approx. 1¼ whorls, smooth. Teleoconch of a further 4¾–5 whorls; appearing smooth, but microsculptured by numerous, very fine, close-set axial riblets, and even finer microscopic spiral threads; axial riblets becoming less regular with growth and resembling fine, uneven growthlines on last adult whorl, spiral sculpture persisting throughout and extending on to base. Aperture elongate-ovate; somewhat oblique to vertical axis of shell; peristome incomplete, simple and thin; no subterminal thickening evident inside outer lip; upper part of columella reflected and compressed against preceding whorl such that its edge is narrow (pleat-like in some specimens) and the umbilicus restricted to a very narrow, tube-like channel.

Shell somewhat lustreless rather than glossy; predominantly mauve-brown in the freshest specimens, with some axial variations in intensity particularly on middle spire whorls; paler pinkish brown to fawn apically.

Dimensions: Holotype, height 16.9 mm, max. diameter 8.5 mm; largest specimen, height 17.5 mm.

Holotype: MADAGASCAR: Central W Madagascar, ca 60 km E of Maintirano, E of Belitsaka, E part of Tsingy Beanka, 18.06145°S 44.52595°E, ca 450 m, in leaf-litter and tsingy slots in comparatively lush tall dry deciduous/evergreen forest on south-facing hill, 2.X.2006, O. Griffiths, R. Randalana, D. Herbert & L. Davis, st'n 12/06 (AMS C.469591).

Paratypes: St'n R02/10 (NMSA L8469/T2897, 1 specimen; AMS C.469584, 4 specimens; MNHN IM2010-20069, 1 specimen).

Additional locality data: Tsingy Beanka: st'ns 03/10, 11/10.

Distribution: Evidently a narrow-range endemic; known only from the Tsingy Beanka.

Habitat: Fresh dead shells have been found in tall, relatively lush dry deciduous and evergreen forest. No living specimens known.

Remarks: The only comparable species known from Madagascar is C. rufoniger (Reeve, 1849), but that species differs in having more rounded whorls, a less elongate shape and a darker, chestnut brown colour (Fig. 7D, E). It also lacks spiral sculpture, and has a wider umbilicus and a thickened white varix inside the outer lip at maturity. C. rufoniger has been mostly recorded from north-eastern Madagascar (Fischer-Piette et al. 1994), but we can also confirm its presence at Antsingimavo (st'ns 04/06, 06/06), Tsingy Beanka (st'ns 01/09, 02/09, 09/09) and in the Tsingy de Bemaraha (Manombolo River).

In the absence of anatomical data, our referral of this species to Conulinus is tentative. In its shape and spiral microsculpture, C. randalanai also resembles some species of Rachis Albers, 1850, but it lacks the colour pattern of dark spots and/or spiral bands commonly seen in species of that genus. Indeed, the referral of C. rufoniger to Conulinus also requires confirmation.

Clavator griffithsjonesi: Emberton 1999: 93, figs 13, 14. Type loc: Madagascar: N Bemaraha Reserve (18°1′S 44°31′E) [= the area now known as Tsingy Beanka].

Morphological notes:

External features (Fig. 25D): Head-foot mostly greyish cream with pedal margin tinged orange-brown; dorso-lateral areas of neck yellowish, mid-dorsal region greyish; distal half of optic tentacles grey.

Distal genitalia (Fig. 11): Penis slender and cylindrical, with relatively muscular wall; apical ⅔ comprising a blind ending caecum, above insertion of epiphallus; retractor muscle inserted at apex of caecum; interior of penis with approx. 6 well-developed, longitudinal pilasters; epiphallus somewhat recurved at its insertion, opening into a deep cleft in one pilaster, near to base of penis; pilasters dividing and anastomosing somewhat in caecum. Epiphallus extremely long and convoluted, its convolutions and those of vas deferens enveloped in membranous covering of connective tissue and attached to lower spermoviduct and free oviduct; a short flagellum present at junction of vas deferens and epiphallus; interior wall of epiphallus with one large longitudinal pilaster and 6 or 7 smaller longitudinal ridges, these continue into flagellum, evanescing near its tip; vas deferens discharges into epiphallus via a pore situated on large pilaster; vas deferens passing over and down lower sperm-oviduct to its origin at base of prostate; lumen of vas deferens for the most part simple, but broadening just prior to junction with epiphallus, and inner wall with 3 longitudinal folds each with side branches. Genital atrium short and simple; bursa copulatrix duct arising after a short vagina; duct very long, of more or less even width, its wall relatively sturdy; bursa copulatrix situated just below level of albumen gland, bean-shaped with a slightly pointed apex; bursa and its duct brownish in colour. Free oviduct short.

Locality data: Tsingy Beanka: st'ns 11/06, 12/06, 15/06 (subfossil), 16/06, 18/06, 06/09, 07/09, 08/09 (subfossil and fresh), 09/09.

Distribution: Evidently a narrow -range endemic; not found in either the Tsingy de Bemaraha or at Antsingimavo, and currently known to occur only in the Tsingy Beanka.

Habitat: Mostly found in tall deciduous forest growing on limestone in the southern areas of Tsingy Beanka; less common as one moves north. Buries shallowly in leaf-litter during the dry season.

Remarks: A characteristic element of the Tsingy Beanka malacofauna and the only species of Clavator recorded from central western Madagascar.

The distal genitalia closely resemble those figured by Schileyko (1999) for C. eximius (Shuttleworth, 1852). Fischer-Piette et al. (1975) illustrated the genitalia of two further Clavator species, of these C. clavator (Petit de la Saussaye, 1844) is similar to C. griffithsjonesi, but it has a more slender bursa copulatrix duct. These authors did not differentiate between an epiphallus and vas deferens in C. clavator, neither did they report a flagellum at the junction of the epiphallus and vas deferens, but this may have been overlooked. C. moreleti (Deshayes, 1851) differs considerably in having a much shorter epiphallus/vas deferens that inserts just below the apex of the penis. It also has a shorter, very slender bursa copulatrix duct.

Etymology: Named for Aldus Andriamamonjy, Executive Director of Biodiversity Conservation Madagascar that manages and protects the forests of the Tsingy Beanka.

Diagnosis: Shell lenticular, periphery rounded; aperture strongly descendant; umbilical width moderate; whitish to fawn, characteristically patterned with 3 or 4 dark brown spiral bands, 1 or 2 above periphery, 2 below; sculpture of close-set, incised spiral striae; apertural rim reflected.

Description:

Shell: Medium sized, lenticular (H:D=0.489–0.586); whorls slightly flattened, periphery rounded; suture weakly indented, final part of last adult whorl descending conspicuously prior to aperture; umbilicus of moderate width, steep-sided and distinctly narrower internally. Protoconch of ca 1 ½–2¾ whorls, superficially etched in most specimens but some individuals with evidence of fine, close-set spiral threads on last whorl; junction with teleoconch usually ill-defined. Teleoconch of a further 2¼ whorls; sculptured by numerous, close-set, incised spiral striae; striae crossed by frequent fine, irregular growth-lines rendering the former wavy; basal sculpture similar, but weakening at umbilical rim and evanescing within. Aperture elongate-ovate, strongly oblique to vertical axis of shell; peristome incomplete, interrupted in parietal region, elsewhere its rim reflected, forming a flaring lip.

Shell somewhat glossy; embryonic whorls buffish brown, slightly darker below suture; first teleoconch whorl with two dark brown spiral bands, lower one broad, situated just above abapical suture, the other narrower, lying a short distance below adapical suture; interval between upper brown band and suture almost white; upper brown band usually fading and disappearing with growth (sometimes within first half whorl), but persisting throughout in some individuals; ground colour becoming paler with growth, a rather uneven dirty white on last adult whorl; base with two further dark brown spiral bands, one just below periphery (emerging close to insertion of outer lip), the other midway between this and umbilical rim; ground colour between supra- and sub-peripheral brown lines paler, almost white; pale subsutural zone persisting throughout. Aperture lip white, colour bands clearly visible internally.

Dimensions: Holotype (largest specimen), max. diameter 29.3 mm, height 15.1 mm.

Holotype: MADAGASCAR: Central W Madagascar, ca 60 km E of Maintirano, southern part of Tsingy Beanka, S side of Tana—Maintirano road, in tall moist forest growing on limestone on south-facing slopes, above N bank of Kimanambolo River, 18.06178°S 44.52494°E, ca 330 m, iv.2010, R. Randalana, st'n R02/10 (AMS C.474164).

Paratypes: Same data as holotype (TMAM T162, 1 adult specimen); st'n R03/98 (NMSA L8441/T2657, 2 adult specimens); st'n 04/06 (AMS C.469582, 1 adult specimen); st'n 16/06 (NMSA L7128/T2656, 1 subadult specimen); st'n R04/09 (MNHN IM-2010-20070, 1 adult specimen); st'n R01/10 (AMS C.469581, 3 adult specimens).

Additional locality data: Tsingy Beanka: st'ns 13/06, 16/06, 02/09, 08/09 (subfossil), R04/09, R01/10.

Distribution: Fresh material has been found only in the Tsingy Beanka. A single subfossil shell is known from Antsingimavo, but the species is now perhaps extinct there. Not recorded from the Tsingy de Bemaraha.

Habitat: Fresh dead shells found most commonly in and amongst limestone rocks, predominantly in the taller moister forests of the southern part of Tsingy Beanka. Not yet found alive.

Remarks: Compared to other spirally banded Ampelita species, the banding pattern of A. andriamamonjyi is distinctive. A. akoratsara Emberton, 1999 (from Marojejy in far north-eastern Madagascar) has a somewhat similar pattern of dark brown spiral lines with whitish subsutural and peripheral bands, but it has a sharply keeled body whorl and lacks the mid-basal brown spiral band of A. andriamamonjyi. Unlikely to be confused with any other known Ampelita species.

Ampelita decaryi: Fischer-Piette 1952: 13, pl. 1, figs 7–9; Emberton 1990: fig. 4d, 1994: 176; Fischer-Piette et al. 1994: 97, pl. 7, figs 4–16. Type loc: Madagascar.

Locality data: Antsingimavo: st'n 04/06. Kelifely Plateau: st'ns 08/05, 10/05. Tsingy de Bemaraha: st'n 15/96.

Distribution: Restricted to central western Madagascar; currently recorded only from Tsingy de Bemaraha and Antsingimavo. Not yet recorded from Tsingy Beanka, but known in subfossil form from the Kelifely Plateau. A record from the Ambositra area (Emberton 1994) almost certainly represents A. caderyi (see below).

Habitat: Dry mixed deciduous-evergreen forest on karst outcrops. No living specimens found, but considerable numbers of empty shells were collected from slots within the tsingy and under overhangs.

Remarks: The holotype of this species had no provenance beyond ‘Madagascar’, but Fischer-Piette (1952) mentioned a young individual from ‘Antsingy (Madagascar Ouest)’. Emberton (1990) and Fischer-Piette et al. (1994) placed this locality in the region of Tsingy de Bemaraha and additional material has since been found there (Griffiths, st'n 15/96). Emberton (1994) also identified under this name specimens from non-calcareous, rain forest habitats in the Ambositra area (Fianarantsoa Province). However, in reality this latter material is more probably referable to A. caderyi FischerPiette et al., 1994, the type locality for which lies in the same vicinity. Although they are undoubtedly similar, the differences between the two taxa were clearly stated by Fischer-Piette et al. (1994).

In terms of shape and coloration, the Antsingimavo material closely resembles the holotype of A. decaryi figured by Fischer-Piette (1952). However, whilst some adult shells in the Antsingimavo population match the holotype in size (max. diameter 35 mm), most are somewhat larger (max. diameter reaching 42 mm). The abundance of empty shells indicates that the species was once not uncommon at this locality. Though much of this material is clearly old, some specimens were of fresh appearance and retained the periostracum, indicating that the species is probably still extant at the site, even though we found no live specimens during our survey. Subfossil shells from the Kelifely Plateau (Fig. 13G) are indistinguishable from the Antsingimavo material, except that the colour pattern is much faded.

Ampelita (Eurystyla) griffithsi: Emberton 1999: 91, figs 11, 12.

Locality data: Tsingy Beanka: st'n R01/11.

Distribution: Previously known from Kirindy (near Morondava) and the southern and central areas of the Tsingy de Bemaraha. Now known also from the southern Tsingy Beanka.

Habitat: Deciduous scrub, semi-deciduous forest and riverine gallery forest (Emberton 1999).

Remarks: The occurrence of A. griffithsi in riverine forest along the Namela River on the southern boundary of Tsingy Beanka Reserve represents a considerable northern range extension for the species.

Etymology: Named for Linda Davis, manager of the Mollusca collection at the KwaZuluNatal Museum and one of the members of the team that discovered this species.

Diagnosis: Shell discoidal, spire flat or nearly so, periphery rounded; aperture strongly descendant with reflected rim; umbilicus wide; surface rough, sculptured by raised collabral vermiform granules; lustreless, mid-brown with whitish, flake-like markings and a pale peri-umbilical band.

Description:

Shell: Medium sized, relatively thin, discoidal with very low spire (H : D=0.357–0.485); periphery at or just above mid-whorl, rounded or weakly angled; a very weak supraperipheral gutter evident in occasional individuals, particularly near start of last whorl; suture indented, final part of last adult whorl descending steeply prior to aperture; umbilicus wide, funnel-shaped. Protoconch of ca 1¼–1½ whorls, the first smooth, thereafter with numerous, irregular, axially elongate granules; junction with teleoconch ill-defined. Teleoconch of a further 2½ whorls; with irregular growth-lines and an uneven sculpture of raised vermiform granules, in a primarily collabral alignment (Fig. 14D); surface thus rendered rough to the touch; granules not simply periostracal, but present on underlying shell; this sculpture continues onto base and into umbilicus. Aperture elongate-ovate, strongly oblique to vertical axis of shell; peristome incomplete, interrupted in parietal region; rim of peristome reflected forming a flaring lip.

Shell lustreless, covered with a predominantly mid-brown periostracum when fresh, with irregular, pale, flake-like markings; underlying shell mostly pale with darker brownish spiral bands either side of a pale, peri-umbilical band; sometimes also darker behind flared aperture lip. Aperture lip white, interior greyish brown in fresh material.

Dimensions: Holotype, max. diameter 30.5 mm, height 12.6 mm; largest specimen, max. diameter 31.4 mm, height 12.7 mm.

Holotype: MADAGASCAR: Central W Madagascar, ca 10 km NE of Belitsaka and ca 60 km E of Maintirano, E side of Tsingy Beanka, in leaf-litter and amongst limestone boulders in tall moist east-facing forest growing on limestone, above Bokarano River Cave, 17.90568°S 44.48822°E, ca 230 m, 29.X.2009, O. Griffiths, D. Herbert, L. Davis & R. Randalana, st'n 07/09 (AMS C.474167).

Paratypes: Same data as holotype (NMSA L8468/T2903, 1 adult specimen); st'n 07/10 (AMS C.469580, 3 adult specimens); st'n 09/10 (AMS C.469579, 1 adult specimen); st'n 07/10 (TMAM T163,1 adult specimen).

Distribution: Evidently a narrow-range endemic, currently known only from Tsingy Beanka; not yet known from either Tsingy de Bemaraha or Antsingimavo.

Habitat: Known only from fresh dead shells collected in leaf-litter in tall, east-facing, evergreen forest in the central part of Tsingy Beanka.

Remarks: With its relatively small, very depressed shell and rough, vermiform microsculpture, A. lindae is a distinctive species. A. granulosa (Deshayes, 1840) (from the north-eastern tip of Madagascar), another species with coarse microsculpture, is much larger and has distinct periostracal bristles arising from the granules, a feature not evident in the present species.

Additional material resembling A. lindae has been found as subfossils in the Kasijy Forest (Kelifely Plateau). These are larger (max. diameter 32.9–35.0 mm, height 15.3–17.9 mm) than the present material but are clearly morphologically close to it. The material available, however, is inadequate to permit thorough study and meaningful comparison.

Etymology: Named after the type locality, Tsingy Beanka.

Diagnosis: Profile distinctive due to low spire, strongly shouldered whorls and descendant suture; umbilicus wide; protoconch with close-set axial riblets; teleoconch with close-set lamellate axial pliculae; lustreless, more or less uniformly mid to dark brown.

Description:

Shell: Relatively small with sharply angled periphery situated well above mid-whorl; spire very low, frequently almost flat; apical surface of whorls weakly convex, becoming slightly concave toward periphery; suture shallowly indented, but progressively descending below peripheral keel on last adult whorl giving shell a stepped profile; umbilicus wide, its rim roundly angular. Protoconch of 1¼–1½ whorls, max. diameter variable 3.7–4.1 mm; initially smooth, rather flat and somewhat sunken, thereafter more convex, bearing numerous, close-set, curved, axial riblets; riblets occasionally bifurcating or anastomosing (Fig. 17A). Teleoconch of a further 2–2¼ whorls; sculptured by closeset, axial pliculae, each with a thin periostracal crest in living specimens, rendering the pliculae somewhat lamellate (Fig. 17B); growth irregularities frequent; basal sculpture the same, continuing into umbilicus. Aperture rounded basally, somewhat angled at periphery and flattened above this; strongly oblique to vertical axis of shell; peristome incomplete, interrupted in parietal region; rim of peristome slightly thickened and flaring in adult, more strongly so basally.

Shell lustreless with a well-developed, predominantly mid to dark brown periostracum when fresh; slight radial unevenness in intensity; apical whorls often slightly paler; umbilicus commonly darker internally, its margin sometimes delineated by a paler band, but this rarely evident in fresh material.

Dimensions: Holotype, max. diameter 17.7 mm, height 8.0 mm; largest specimen, max. diameter 19.1 mm.

External features: Data on coloration of living animals not available; in preserved specimens head-foot mostly dark brown to blackish, but with evidence of a paler longitudinal band extending down neck from each optic tentacle; skin texture uniformly granular; lining of mantle cavity heavily pigmented with black and patterned with pale circular blotches, mostly on the right (upper) side.

Distal genitalia (Fig. 16): Relatively simple and largely typical of the genus. Penis short to moderate in length (4.0–5.0 mm) and rather stout; vas deferens running beside and loosely attached to its basal portion, but becoming more closely attached near penis apex; at apex of penis vas deferens turns sharply back on itself and broadens noticeably before inserting some distance below penis apex; this latter portion, perhaps constituting an epiphallus, has a thicker, pale flesh-coloured wall and is fused to outer wall of penis. Penis retractor muscle attaches apically, enveloping recurved portion of vas deferens and penis apex. Interior of penis with a Y-shaped longitudinal fold in the centre of which is a distinct, rounded papilla at insertion of epiphallus; this primary fold bordered on each side by a further longitudinal fold; remainder of lumen largely smooth, but with evidence of microscopic papillation in apical region. Genital atrium and vagina, simple and short; bursa copulatrix duct long, basal portion somewhat broader; bursa itself of moderate size, ovate to subcircular.

Holotype: MADAGASCAR: Central W Madagascar, ca 60 km E of Maintirano, in tall dense dry forest growing above cliffs on E side of Tsingy Beanka at Andohanandranogedro, 18.05028°S 44.53786°E, 380 m, iv.2009, R. Randalana, st'n R04/09 (AMS C.474166, body in alcohol).

Paratypes: Same data as holotype (NMSA L8504/T2983, 9 specimens, bodies in alcohol; NHMUK 20120014, 1 specimen); st'n 07/10 (NMSA L8525/T2980, 6 specimens); st'n 07/09 (NMSA L8501/T2981, 4 specimens, one in alcohol); st'n R01/09 (NMSA L8507/T2982, 2 specimens); st'n 01/10 (AMS C.469583, 4 specimens; TMAM T165, 1 specimen); st'n 09/09 (MNHN IM-2010-20071, 1 specimen).

Additional locality data: Tsingy Beanka: st'ns 11/06, 09/09, 01/10.

Distribution: A narrow-range endemic currently recorded only from Tsingy Beanka.

Habitat. Fresh dead shells found most commonly in and amongst limestone rocks predominantly in the taller moister forests. Living individuals usually found in leaf-litter.

Remarks: In terms of its shape and coloration, A. beanka resembles A. milloti and A. namerokoensis (below), both of which occur in the Bemaraha-Beanka region. A. namerokoensis differs in lacking significant axial sculpture on the protoconch and in having distinct spiral microsculpture on the teleoconch (Fig. 17E, F). It also attains a larger size, has the peripheral keel closer to mid-whorl, has a somewhat narrower umbilicus, and the suture, if descendant at all, is at most weakly so and then only near the end of the last adult whorl.

Ampelita milloti is perhaps more similar in having axial riblets on the protoconch and lacking spiral microsculpture, but its teleoconch sculpture is finer, the axial elements more irregular and fragmented, appearing granular rather than lamellate (particularly evident on the base). Furthermore, as in A. namerokoensis, the suture of A. milloti is never strongly descendant. The smaller size, shouldered profile, strongly descendant suture and lamellate axial sculpture of A. beanka render it distinctive. The descent of the suture below the peripheral keel, though characteristic of the species and well developed in the holotype, is somewhat variable in its extent, but usually commences at least one half whorl prior to the aperture. The position of the peripheral keel is also somewhat variable, lying closer to mid-whorl in some specimens (Fig. 15D).

We have considered the possibility that these differences may reflect ecological factors and that the stepped profile may result from damage to the mantle edge at the suture, as is evident in some specimens of both A. milloti and A. namerokoensis. However, the stepped profile of A. beanka is present in specimens showing no growth scars indicative of earlier damage to the outer lip, and we can consistently discriminate between A. beanka and the other two species in terms of the microsculptural differences detailed above. There are also significant differences evident in the morphology of the penis (see below). All three species occur in the Tsingy Beanka and have been found to cooccur at a number of sampling sites. Emberton (1999) described a similar lamellar axial microsculpture in A. analamerae Emberton, 1999, from far north-eastern Madagascar, but that species is larger, is keeled at mid-whorl and has a much more prominent spire and narrower umbilicus.

Ampelita milloti: Fischer-Piette 1952: 34, pl. 3, figs 31–34; Fischer-Piette et al. 1994: 123, pl. 15, figs 1–4. Type loc: ‘Gorge de Salapango [= Salapanga], Bemaraha’, Madagascar.

Morphological notes:

External features (Fig. 25E): Head-foot uniformly dark, charcoal-grey to black; skin texture uniformly granular throughout; lining of mantle cavity heavily pigmented with black and patterned with pale circular blotches (observations based on a single livecollected individual).

Distal genitalia: The single preserved specimen available (shell diameter 19.2 mm) possessed an immature reproductive tract. The distal genitalia were thus poorly developed and inadequate for comparative study. From what could be seen of the penis, it appeared similar to that of A. namerokoensis.

Locality data: Antsingimavo: st'ns 4/06, 8/06 (all subfossil). Tsingy Beanka: st'ns 12/06, 14/06, 16/06, 18/06, 02/09, 06/09, 07/09, 08/09, 01/10, 06/10, 07/10, 08/10, 09/10. Tsingy de Bemaraha: st'ns 07/95, 10/95, 14/95, 18/95, 19/95, 9/96, 10/96, 12/96. South bank of Tsiribihina River: st'ns 01/99LP, 02/99LP.

Distribution: Evidently a narrowly endemic species, currently known only from the south bank of Tsiribihina River, Tsingy de Bemaraha and Tsingy Beanka. Subfossil at Antsingimavo where it now appears to be locally extinct.

Habitat: Living specimens are most commonly found amongst limestone rocks and in leaf-litter. In Tsingy Beanka, it occurs predominantly in the taller, moister forests of the southern part.

Remarks: Shell lenticular, of moderate size (max. diameter <33 mm), with a very low spire and sharply angled periphery; last whorl descending at most slightly just prior to aperture; uniformly tan-brown with a yellow to white band around umbilicus. Specimens from Tsingy Beanka are noticeably smaller than those from Bemaraha and Antsingimavo (maximum adult diameter 20–25 vs 28–32 mm).

Resembles A. namerokoensis (below) in size and shape, but easily separated from that species due to the almost complete absence of microscopic spiral striae (some traces may be visible on the base). Instead the microsculpture of A. milloti comprises irregular, elongate granules aligned in a roughly radial (collabral) pattern (Fig. 17D). Furthermore, A. milloti attains a somewhat larger size and has a wider umbilicus than A. namerokoensis, and its protoconch is larger (diameter approx. 4.4 vs approx. 3.5 mm) and bears distinct close-set axial riblets (Fig. 17C), whereas that of A. namerokoensis is more or less smooth (Fig. 17E). Features separating A. milloti from A. beanka are discussed above.

Ampelita namerokoensis: Fischer-Piette 1952: 35, pl. 3, figs 35–39; Fischer-Piette et al. 1994: 123, pl. 15, figs 5–8. Type loc.: ‘Gorges de Salapango [= Salapanga], Bemaraha’, Madagascar.

Morphological notes:

External features (Fig. 25F): Head-foot mostly dark grey-brown with uniformly granular skin texture; optic tentacles slightly paler, running into similarly pale bands along neck; skin granules with microscopic ochre-brown pigment granules; lining of mantle cavity with some black pigmentation (not dense) and a pattern of pale circular blotches.

Distal genitalia (Fig. 20): Resembling those of A. beanka, but differing considerably in penis morphology, particularly its internal structure. Penis shorter (ca 3.2 mm) and more slender than in A. beanka, and the apical region less swollen; vas deferens follows a similar path alongside penis, running to its apex and then recurving before inserting subterminally via a short, somewhat broader, pale flesh-coloured epiphallus; details of recurved vas deferens and epiphallus mostly concealed by attachment of retractor muscle. Interior of penis with a small conical papilla at insertion of epiphallus, from which a single mid-line fold runs to penis base; additional concentric folds surround papilla on both sides, these converging and evanescing toward penis base; the resultant pattern of folds differing considerably from that of A. beanka.

Locality data: Tsingy Beanka: st'ns 03/06, 11/06, 12/06, 14/06, 16/06, 18/06, 02/09, 06/09, 07/09, 08/09, 09/09, 11/09, 01/10, 02/10, 05/10, 07/10, 08/10, 09/10, 10/10. Bemaraha: st'ns 14/95, 09/96, 12/96.

Distribution: Restricted to central western Madagascar, with reliable records only from the Tsingy de Bemaraha and Tsingy Beanka; not found at Antsingimavo and, despite its name, evidently does not occur in Nameroko [Namoroka] (see Remarks below).

Habitat: Living specimens are found most commonly amongst limestone rocks and in leaf-litter. In Tsingy Beanka, it occurs mostly in the southern region, in taller, moister forests.

Remarks: Shell lenticular, of moderate size (max. diameter <26 mm, but rarely more than 23 mm), carinate at periphery; uniformly light brown when fresh, with a pale yellowish band around the umbilicus. Protoconch essentially smooth (Fig. 17E), but sometimes with microscopic traces of oblique, close-set striae on last embryonic whorl, forming an extremely fine criss-cross pattern. Teleoconch with fine spiral sculpture (Fig. 17F).

The choice of name for this species is puzzling since the type locality [Salapanga] is in the Tsingy de Bemaraha. Fischer-Piette (1952) mentioned material from Ambongo (collected by G. Petit and H. Perrier de la Bâthie), which he equated with the ‘Tsingy de Nameroko’. Elsewhere, however, Fischer-Piette and Bedoucha (1965: 62) stated that Salapanga [known to be in the Bemaraha] was also in the Ambongo region, suggesting in this case that Ambongo equates with Bemaraha. In line with this, S. Goodman (pers. comm .2010), confirmed that Ambongo has been used for both Bemaraha and Namoroka. There is therefore some doubt regarding the occurrence of this species in Namoroka and despite survey work (Griffiths in 1997 and Emberton in 2007), no specimens have been found there.

Additional material from the Kelifely Plateau (st'ns 06/05, 10/05) resembles this species in having spiral sculpture, but the protoconch is sculptured with distinct axial riblets like that of A. milloti. At this stage its identity remains puzzling. Further subfossil or very old dead specimens from limestone caves in the Anjajavy—Narinda area, northeast of Mahajanga (Griffiths pers. observ.) may also be referable here.

Bathia madagascariensis: Robson 1914: 383, pl. 35, figs 11–13; Fischer-Piette et al. 1966: 11; 1994: 203, text-fig. 94, pl. 31, figs 10–12; Schileyko 2002: 1242, fig. 1633. Type loc.: ‘Namoroku (Ambongo)’ [= Namoroka].

Locality data: Namoroka: st'n 930/97. Tsingy Beanka: st'ns 03/12, 06/12.

Distribution: Recorded only from the Tsingy de Namoroka Strict Nature Reserve and Tsingy Beanka in north-western Madagascar.

Habitat: Dry deciduous forest on limestone; dead shells have been found reasonably commonly at two sites in the southern part of Tsingy Beanka, in a cave and under overhangs. The snail occurs in similar conditions at Namoroka.

Remarks: Bathia madagascariensis was previously known only from the Namoroka Reserve, which lies approx. 180 km to the north-east of Tsingy Beanka. The present record of its occurrence in Tsingy Beanka represents a considerable southward range extension. Although only dead shells were found at this locality, some of these are fresh, indicating that the species is almost certainly still extant there.

Specimens from Tsingy Beanka attain a larger size than those at Namoroka (max. height 12.9 mm, max. diameter 25.5 vs 10.5 mm and 19.5 mm respectively at Namoroka). Furthermore, in Tsingy Beanka material the spire whorls are raised above the final whorl, but are level with it in Namoroka specimens (compare Figs 21A and 21D). In the absence of evidence to suggest otherwise, we consider these differences to reflect geographical variation. As noted by Fischer-Piette et al. (1966) and Schileyko (2002), determination of the true affinities of this species must await morphological examination of the soft parts. Its placement in the Helicarionidae follows Fischer-Piette et al. (1994), but must be considered provisional.

Kalidos griffithshauchleri: Emberton 2002: 259, fig. 1. Type loc.: 15km E Antsalova, nr Tsingy de Bemaraha.

Morphological notes:

External features (Fig. 25G): Head-foot grey, with pale grey tubercles clearly delineated by dark grey skin grooves; lateral pedal grooves and peripodial groove distinct; caudal pit well developed but caudal horn not prominent; mantle lobes pale grey, minutely specked with darker spots.

Distal genitalia (Fig. 22): The largest preserved specimen available (shell diameter 54 mm) proved to have a subadult or inactive reproductive tract. The organs of the distal tract were clearly differentiated, but the sperm-oviduct was immature or inactive. We illustrate the features observed, but caution that this may not truly reflect the mature condition.

Penis long (ca 21 mm) and slender, surrounded basally by a thin sheath; proximal end slightly swollen prior to junction with very long, slender epiphallus; internally this swollen region with a well-developed penial verge extending from insertion of epiphallus; verge digitiform, the distal third with a longitudinal cleft through which epiphallus discharges; hind end of cleft preceded by a raised boss; inner lining of penis comprising a mosaic of irregularly shaped pits; epiphallus with a sharp bend at insertion of penial retractor muscle and thus divided into proximal and distal limbs; proximal limb somewhat longer than distal one; a long narrow flagellum arises at junction of vas deferens and epiphallus; basal part of flagellum running close to vas deferens and both embedded in membranous sheath; apical half of flagellum free and sinuous; vas deferens continues beside penis and inside its basal sheath before recurving and running beside vagina; vagina long, its proximal end convoluted before insertion of bursa copulatrix duct; bursa duct, somewhat broader basally, but narrowing alongside sperm-oviduct. Sperm-oviduct poorly developed. Bursa copulatrix and proximal portions of reproductive tract missing.

Locality data: Tsingy Beanka: st'ns 03/06, 12/06, 14/06, 16/06, 17/06, 18/06, 02/09, 05/09, 06/09, 07/09, 08/09, 09/09, 01/10, 07/10. Tsingy de Bemaraha: st'ns 07/95, 18/95, 10/96, 12/06.

Distribution: A regional endemic; known only from Tsingy de Bemaraha and Tsingy Beanka.

Habitat: Dry deciduous and evergreen forest on limestone; dead shells are common in caves and under overhangs. During dry periods living specimens aestivate in caves and deep within slots in the tsingy, attached to the rock well above ground level. They emerge after rains and can be locally common.

Remarks: This, the largest species of Kalidos, is a conspicuous element of the Bemaraha-Beanka karst formations. Specimens from the southern part of Bemaraha, near Bekopaka, are noticeably smaller than those occurring further north with a max. diameter of 41– 46 mm (vs 64 mm in the Tsingy Beanka). The genital anatomy is broadly consistent with that of other species of Kalidos, although the penis and vagina are particularly long.

Etymology: Named for Mary-Ann Stanley, wife of Owen Griffiths.

Diagnosis: Shell globose-lenticular, periphery rounded, aperture weakly descendant, umbilicus narrow; sculpture of fine, uneven spiral lines crossed by growth-lines; lustreless, pale coffee-brown, with a bold white spiral band just above periphery, bordered above and below by thinner, dark brown spiral lines.

Description:

Shell: Medium sized, globose-lenticular with a relatively elevated spire (H:D=0.57– 0.67); periphery at mid-whorl, rounded in adults, somewhat angled in juveniles; suture indented but not strongly so, situated at whorl periphery, occasionally slightly descendant prior to aperture; umbilicus narrow. Protoconch of approx 1¼ whorls, smooth except for numerous, close-set, microscopic, spiral threads; junction with teleoconch often indistinct. Teleoconch of a further 3½–4 whorls; initially lustreless and smooth, save for weak growth-lines, but with fine, irregular spiral sculpture developing with growth; last adult whorl with surface cut by somewhat stronger, rather uneven spiral lines, crossed by irregular growth-lines, creating low, weakly and unevenly pustular spiral ridges (Fig. 23K), these more distinct toward periphery, but evanescing on base which is more glossy and sculptured only with close-set, microscopic, incised spiral threads, rendered irregularly undulant by growth-lines. Aperture ovate-reniform, peristome strongly oblique to vertical axis of shell, interrupted by base of penultimate whorl; outer lip simple and thin; upper part of columella lip reflected and partially covering umbilicus.

Shell strikingly coloured, with a bold white spiral band (1.0–2.0 mm wide) just above periphery, bordered above and below by thinner, dark brown spiral lines; white band and upper brown line visible on penultimate whorl, but generally absent on spire whorls; remainder of shell rather unevenly washed with buff to pale coffee-brown in fresh specimens, fading to dirty white with time and loss of periostracum. Colour bands often ceasing a short distance before lip edge, and clearly visible inside aperture. In the largest specimens, an additional ⅛ whorl is added to the mature lip (Fig. 23I). These may represent individuals that survive through the dry season after maturity has been reached and begin another phase of growth when the rains return the following year.

Dimensions: Holotype, max. diameter 27.3 mm, height 17.7 mm; largest specimen, max. diameter 29.4 mm, height 18.8 mm.

External features (Fig. 25H): Head-foot mostly pale, but somewhat darker anteriorly, with yellowish white tubercles contrasting with darker, brownish skin grooves; lateral pedal grooves and peripodial groove distinct; caudal pit and surmounting horn well developed; optic tentacles darker greyish brown; mantle lobes pale with numerous yellowish white pigment granules.

Distal genitalia (Fig. 24): Penis of moderate length (approx. 12.5 mm), apical portion swollen and with a deep indentation; basal ³/₄ encased in a thin sheath; apical bulb of penis containing a well-developed verge; verge much contracted but possessing a deep longitudinal groove confluent with opening of epiphallus; lower portion of penis with 5 or 6 broad, low folds with a microscopically velvety texture; epiphallus cylindrical, with a sharp bend at insertion of penial retractor muscle and thus divided into proximal and distal limbs; proximal limb slightly shorter than distal one (distal limb might also be considered part of penis rather than epiphallus); a short flagellum, comprising just over one tight loop, arises at junction of vas deferens and epiphallus; flagellum and vas deferens wrapped in connective tissue, but flagellum not connected to penis by muscle bands; lumen of flagellum with a rod-like process extending from its blind end; vas deferens passes along vagina and free oviduct to its origin at base of sperm-oviduct; retractor muscle of right optic tentacle passes to right of penis, i.e. between penis and vagina; bursa copulatrix large, narrowing apically and with a short broad duct; wall of duct thick and muscular, lined internally with longitudinal folds, wall of bursa much thinner; bursa with one moderately fresh allospermatophore and the remains of at least one more; free oviduct swollen prior to its junction with vagina (peri-vaginal or oviducal gland); sperm-oviduct well developed, twisted and with numerous superficial folds. Spermatophore with well-developed capsule (head and body) and a looped tail piece corresponding with shape of flagellum; tail piece with prominent flange-like spiral ridge; a small ‘filling nipple’ present at level of vas deferens.

Holotype: MADAGASCAR: Central W Madagascar, ca 60 km E of Maintirano, S part of Tsingy Beanka, S side of Tana-Maintirano road, above N bank of Kimanambolo R., tall moist forest growing on limestone on south-facing slopes, 18.06325°S 44.52861°E, ca 345 m, ii.2010, R. Randalana, st'n R01/10 (AMS C.474168).

Paratypes: Same data as holotype (NMSA L8470/T2904, 10 specimens, body of one in alcohol); 12/06 (NMSA L7193/T2944, 3 specimens, body of one in alcohol); st'n 8/10 (NMSA L8471/T2943, 1 specimen); st'nR01/09(NMSA L8475/T2912, 1 specimen, body in alcohol); st'n 08/09 (AMS C.469578,12 specimens); st'n 03/10 (MNHN IM-2010-20072, 3 specimens; NHMUK 20120015, 3 specimens); st'n 07/09 (TMAM T166, 6 specimens).

Additional locality data: Antsingimavo: st'n 04/06 (subfossil). Tsingy Beanka: st'ns 12/06, 14/06, 15/06, 18/06, 02/09, 06/09, 07/09, 08/09, 09/09, 11/09, 01/10, 04/10, 06/10, 07/10, 08/10, 09/10.

Distribution: Evidently now confined to the Tsingy Beanka, where it is moderately common; not recorded from the Tsingy de Bemaraha, but a single subfossil specimen was found at Antsingimavo.

Habitat: Fresh dead shells are found most commonly amongst limestone rocks, predominantly in the taller moister forests of the southern part of Tsingy Beanka. Living specimens are usually found in leaf-litter. Appears to aestivate sealed to limestone rocks or deep in tsingy slots.

Remarks: In its moderate size and pattern of peripheral banding (two dark brown spiral lines separated by a broader whitish band) this species resembles K. bathensis (Robson, 1914), K bournei Robson, 1914, K. ekongensis(Angas, 1877), K. hova (Odhner, 1919), and K. namorokae Emberton, 2007. In K bournei and K. namorokae, however, the shell is smaller and the upper brown spiral line is situated further from the whorl periphery. In contrast, K. bathensis is larger than the present species, paler in colour and the median spiral band between the brown spiral lines is not distinctly paler than the remaining shell. In addition, it has a third brown spiral line below the suture and the supra-peripheral spiral line is clearly present on the spire whorls.

Undoubtedly, the most similar species in terms of size and colour pattern are K. ekongensis and K. hova, both of which, as presently conceived, are poorly delineated species. In his description of K. hova Odhner (1919) noted a fawn peripheral band on an otherwise brownish shell, but he made no mention of this band being bordered above and below by dark brown spiral lines, neither are these clearly evident in his figure nor in the type material (Fig. 26J–L, syntype, SMNH). He also stated that the shell was smooth and glossy and that the spiral microsculpture was more distinct on the base. This is not the case in K. maryannae in which the shell is lustreless and the spiral sculpture strongest above the periphery of the last whorl.

K. ekongensis is more difficult to assess since the type material is now missing. A paratype reportedly in the NHMUK (Fischer-Piette et al. 1966) is not in fact present there (Ablett pers. comm. Nov. 2011). The original description is not detailed, but the figure shows a shell closely resembling the present material. However, Fischer-Piette et al. (1966) noted, after examination of the NHMUK paratype, that the shell was thin and very glossy. Again this is not a description that would apply to the present material. Fischer-Piette et al. (1966, 1994) interpreted K. ekongensis very loosely, including in it a variety of different forms from widely disjunct localities with widely differing habitats. Almost certainly these are not conspecific and their true identity requires further investigation.

In addition to having relatively coarse spiral sculpture on the last adult whorl, rendering it lustreless, K. maryannae also differs from K. ekongensis and K. hova in having more rapidly expanding whorls. Another distinctive feature of K. maryannae is that the colour bands are evident only on the penultimate and final whorls, the spire whorls being of a uniform colour.

The genital anatomy of K. maryannae conforms to the common pattern evinced by Kalidos species (Fischer-Piette et al. 1975; Schileyko 2002) and is fully consistent with referral of the species to this genus. In this regard it is perhaps most similar to Kalidos oleatus (Ancey, 1902) as figured by Schileyko (2002), but in the present species the flagellum is shorter and more tightly coiled and it is not connected to the penis by muscle bands, and the bursa copulatrix duct is shorter and much broader.