Cyclostoma (Cyclophorus) convexiusculum Pfeiffer, 1855: 104 Cyclophorus convexiusculus var. minor Benson, 1856: 438 Chondrocyclus convexiusculus – Kobelt 1902: 230 Connolly 1939: 536 Herbert & Kilburn 2004: 92 Revision of Chondrocyclus s. l. (Mollusca: Cyclophoridae), with description of a new genus and twelve new species Cole, Mary L. European Journal of Taxonomy 2019 2019-10-22 569 1 92 5XZH9 (Pfeiffer, 1855) Pfeiffer 1855 [512,1075,267,294] Gastropoda Cyclophoridae Chondrocyclus GBIF Animalia Architaenioglossa 8 9 Mollusca species convexiusculus   Figs 4, 5, 8C      Cyclostoma (Cyclophorus) convexiusculum Pfeiffer, 1855: 104( typeloc.: Simonstown [Macgillivray]).   Cyclophorus convexiusculusvar. minor Benson, 1856: 438( typeloc.: Table Mountain [Layard]).     Chondrocyclus convexiusculus– Kobelt 1902: 230. —  Connolly 1939: 536. —  Herbert & Kilburn 2004: 92.    Diagnosis Shell small, depressed, lenticular; protoconch mammillate and tilted; periostracum with axial costae developing at the periphery broad triangular flanges each terminating in a long, hair-like spine; operculum flattened, exterior portion shallowly concave, with step-shaped multispiral lamella terminating in a long solid fringe; radula with three large cusps on second lateral tooth.    Etymology The specific name is derived from the Latin ‘ convex’, meaning ‘arched or vaulted’.    Type material examined   Syntypes   SOUTH AFRICA–  Western Cape• 3 specimens; syntypesof  Cyclostoma (Cyclophorus) convexiusculum Pfeiffer, 1855( Fig. 4A); Simons Bay; [Mrs] Cumingleg.; NHMUK 20120231.   Other material examined   SOUTH AFRICA–  Western Cape• 6 specimens; Cape Peninsula, Simonstown; 34.1912° S, 18.4211°E; M. Connollycoll.; NMSA 2777•  2 specimens; same collection data as for preceding; ex. M. Connollycoll.; NMSA A8004•  11 specimens; Cape Town, 2.8 kmsouth of Miller’s Point, forest in a depression with a few invasive trees (  Eucalyptusand Port Jackson), steep slope with rocks and root buttresses; 34.2507° S, 18.4729° E;  25 Jun. 2011; R. Danielsleg.; thick and moist leaf litter, about a week of rain before collection; ELMD16879•  11 specimens; same collection data as for preceding; ELM W3636•  1 specimenin ethanol; same collection data as for preceding; NHMUK 20120276•  40 specimens; same collection data as for preceding;  1 Feb. 2012; R. Danielsleg.; ELMD16880•  17 specimens; same collection data as for preceding; ELM W3637•  3 specimens; same collection data as for preceding; NHMUK 20120277•  2 specimens; same collection data as for preceding; NMW.Z.2012.065.00007•  5 specimens; DuToits Kloof, Donkerkloof, patch of Southern Afrotemperate forestin steep ravine; 33.7536° S, 19.0696° E;  462 ma.s.l.;  7 Aug. 2014; M. Coleleg.; ELMD17970•  1 specimen; same collection data as for preceding; ELM W3891•  26 specimens; Kogelberg Nature Reserve, small patch of Southern Afrotemperate forestnear Leopards Gorgewaterfall; 34.3409° S, 18.9407°E;  312 ma.s.l.;  12 Aug. 2014; M. Coleleg.; ELMD17955•  22 specimens; same collection data as for preceding; ELMW03876•  22 specimens; Kogelberg Nature Reserve, Oudebosch, patch of Southern Afrotemperate forestin kloof with Oudebos River; 34.3337° S, 18.9487°E;  260 ma.s.l.;  12 Aug. 2014; M. Coleleg.; ELMD17975•  25 specimens; same collection data as for preceding; ELMW03877.    Description SHELL ( Fig. 4B–D). Small, depressed, lenticular, adult diameter 3.97–5.18 mm, height 2.29–3.20 mm, diameter:height 1.59–1.88 (n = 21). Spire little exserted, apex mammillate and tilted ( Fig. 4A, C). Embryonic shell ( Fig. 4E) approx. 2.25 whorls, microscopically malleate, sculpture strongest on earliest part, junction between embryonic shell and teleoconch evident with development of axial costae and threads on teleoconch. Teleoconch comprising 2.25 whorls, convex, rapidly increasing, suture deeply impressed. Aperture circular, last whorl descending near aperture, peristome simple, continuous and free. Umbilicus wide and deep, exposing all the whorls. Periostracum glossy, honey-brown and lacquerlike with lamellate axial costae at regular intervals, 44–61 (n = 16) on last whorl, developing at periphery broad triangular flanges terminating in a long, hair-like spine ( Figs 4F, 8C); intervals between costae with 3–5 indistinct microscopic axial threads. Shell translucent glossy honey-brown or creamy-white when fresh.   Fig. 4.  Chondrocyclus convexiusculus( Pfeiffer, 1855). A. Syntype (NHMUK 20120231). B–K. ELM W3636. B. Dorsal view. C. Aperture view. D. Ventral view. E. Protoconch. F. Detail of axial lamellae of periostracum. G. Portion of radula. H–I. Operculum. J–K. Penis, lateral and dorsal views, showing position on head. Scale bars: A, C = 3 mm; B, D = 2 mm; E = 200 µm; F, J–K = 500 µm; G = 50 µm; H–I = 1 mm. LIVING ANIMAL. Head, tentacles and snout dark grey; underside of foot white. OPERCULUM ( Fig. 4H–I). Duplex, outer portion concave, consists of multispiral lamella with almost five whorls, each step-shaped; the growing edge of the lamellar blade angular and is more or less perpendicular to disc where it is attached; long fringe of fused bristles emanates from outer side of lamellar blade and curves upwards and outwards forming a furrow between fringe and lamellar blade partially covered by top edge of lamellar blade which curves outwards; top edge of lamella projects above fringe; fringe of each whorl fused to lamella of following whorl. RADULA ( Fig. 4G). Rachidian with five cusps, central cusp approx. twice as long as two on either side of it; first and second lateral tooth each with four cusps and a swelling representing the fifth cusp, first three cusps (from centre) increasing in size and fourth considerably smaller. PENIS ( Fig. 4J–K). Shaft more-or-less cyclindrical with slightly swollen distal end and a short intromittent organ.    Distribution and habitat  Western Cape, mountains of the CapePeninsula and north-south running mountains to the east of the CapeFlats. Inland populations appear to be bounded by the upper Breede River valley and coastal populations by the relatively low-lying Agulhas Plain ( Fig. 5). There are no records from the Riviersonderend Mountains.  Western CapeAfrotemperate forest ( von Maltitz et al.2003), very small patches in sheltered ravines; in leaf-litter.    Remarks  Connolly (1929)distinguished this species from  C. alabastrison the basis of the second lateral tooth of the radula, that of  C. convexiusculushaving three large cusps and  C. alabastristwo. This is confirmed by comparing Fig. 4Gand Fig. 7F. There are also differences in the periostracum and operculum discussed under  C. alabastris.The molecular analyses placed  C. convexiusculusand  C. alabastrisin different clades ( Fig. 1). 2429182689 NHMUK Cuming South Africa Simons Bay 8 9 NHMUK 20120231 3 Western Cape syntype 2429182836 NMSA M. Connolly South Africa -34.1912 Simonstown 6 18.4211 Peninsula 8 9 NMSA 2777 6 Western Cape 2429182583 NMSA M. Connolly South Africa -34.1912 Simonstown 6 18.4211 Peninsula 8 9 A8004 2 Western Cape 2429182588 2011-06-25 ELM R. Daniels South Africa Town -34.2507 Port Jackson 6 18.4729 Miller's Point 8 9 11 Western Cape 2429182694 [594,1380,1316,1342] 2011-06-25 ELM R. Daniels South Africa Town -34.2507 Port Jackson 6 18.4729 Miller's Point 8 9 W3636 11 Western Cape 2429182582 [189,1141,1352,1378] 2011-06-25 NHMUK R. Daniels South Africa Town -34.2507 Port Jackson 6 18.4729 Miller's Point 8 9 NHMUK 20120276 1 Western Cape 2429182728 2012-02-01 ELM R. Daniels South Africa Town -34.2507 Port Jackson 6 18.4729 Miller's Point 8 9 40 Western Cape 2429182655 2012-02-01 ELM R. Daniels South Africa Town -34.2507 Port Jackson 6 18.4729 Miller's Point 8 9 W3637 17 Western Cape 2429182639 2012-02-01 NHMUK R. Daniels South Africa Town -34.2507 Port Jackson 6 18.4729 Miller's Point 8 9 NHMUK 20120277 3 Western Cape 2429182592 [456,1378,1459,1486] 2012-02-01 NMW R. Daniels South Africa Town -34.2507 Port Jackson 6 18.4729 Miller's Point 8 9 2 Western Cape 2429182572 2014-08-07 ELM M. Cole South Africa DuToits Kloof 462 -33.7536 Southern Afrotemperate forest 6 19.0696 Donkerkloof 8 9 5 Western Cape 2429182637 2014-08-07 ELM M. Cole South Africa DuToits Kloof 462 -33.7536 Southern Afrotemperate forest 6 19.0696 Donkerkloof 8 9 W3891 1 Western Cape 2429182707 2014-08-12 ELM M. Cole South Africa Kogelberg Nature Reserve 312 -34.3409 Leopards Gorge 6 18.9407 Southern Afrotemperate forest 8 9 26 Western Cape 2429182847 2014-08-12 ELM M. Cole South Africa Kogelberg Nature Reserve 312 -34.3409 Leopards Gorge 6 18.9407 Southern Afrotemperate forest 8 9 22 Western Cape 2429182647 2014-08-12 ELM M. Cole South Africa Kogelberg Nature Reserve 260 -34.3337 Southern Afrotemperate forest 6 18.9487 Oudebosch 8 9 22 Western Cape 2429182595 [378,1177,1744,1771] 2014-08-12 ELM M. Cole South Africa Kogelberg Nature Reserve 260 -34.3337 Southern Afrotemperate forest 6 18.9487 Oudebosch 8 9 25 Western Cape