Anceyoconcha S. Tumpeesuwan & C. Tumpeesuwan, 2020

Nahok, Benchawan, Tumpeesuwan, Chanidaporn & Tumpeesuwan, Sakboworn, 2021, Two new species of genus Anceyoconcha S. Tumpeesuwan & C. Tumpeesuwan, in Nahok et al., 2020 (Gastropoda: Pulmonata: Camaenidae), from northeastern Thailand, Raffles Bulletin of Zoology 69, pp. 555-569 : 559

Anceyoconcha S. Tumpeesuwan & C. Tumpeesuwan , in Nahok, Tumpeesuwan & Tumpeesuwan, 2020

Anceyoconcha S. Tumpeesuwan & C. Tumpeesuwan , in Nahok et al., 2020: 81 (replacement name for Giardia Ancey, 1907 , not Giardia Künstler, 1882 (Metamonada)).

Type species. Bulimus siamensis Redfield, 1853 .

Diagnosis. Shell sinistral, ovate trochoid to elongate conic, with 6–9 slightly convex whorls, semi-transparent, and lustrous. Genital system without dart sac and mucous glands. Flagellum long cylindrical and tapering, distally relatively hook-shaped ( Figs. 4A, B , 5A, B , 6A, B ). Vas deferens long, thin, entering epiphallus laterally. Free oviduct short. Vagina long, stout. Gametolytic duct thickened at base, proximal part wider than distal part; gametolytic sac spear- or dropletshaped. Radula, central tooth symmetric unicuspid, narrowly rounded to lanceolate; lateral teeth oblique unicuspid ( Fig. 5J ) or bicuspid with indistinct or distinct blunt ectocone ( Figs. 4H , 6H ); marginal teeth tricuspid-tetracuspid with finger-shaped ectocone.

Figures

Fig. 4. Anceyoconcha carinata, new species. A, B, genital system, paratype (NHMSU-00037). C–F, inner wall of genital system; C, penis (p) and proximal portion of epiphallus (ep1); D, distal portion of epiphallus (ep2); E, flagellum (fl); F, vagina (v). G, view of transverse rows of radula, with number of lateral and marginal teeth indicated (c = central tooth); H, right side of central tooth and lateral teeth; I, right side of marginal teeth. J, natural habitat and living adult.

Fig. 5. Anceyoconcha elongata, new species. A, B, genital system, paratype (NHMSU-00040) from Phu Po, Kalasin. C, genital system (NHMSU-00042) from Phu No, Kalasin. D, genital system (NHMSU-00046) from Phanom Sawai, Surin. E–H, inner wall of genital system; E, penis (p) and proximal portion of epiphallus (ep1); F, distal portion of epiphallus (ep2); G, flagellum (fl); H, vagina (v). I, view of transverse rows of radula, with number of lateral and marginal teeth indicated (c = central tooth); J, left side of central tooth and lateral teeth; K, right side of marginal teeth.

Fig. 6. Anceyoconcha sp.1. A, B, genital system (NHMSU-00044). C–F, inner wall of genital system; C, penis (p) and proximal portion of epiphallus (ep1); D, distal portion of epiphallus (ep2); E, flagellum (fl); F, vagina (v). G, view of transverse rows of radula, with number of lateral and marginal teeth indicated (c = central tooth); H, left side of central tooth and lateral teeth; I, left side of marginal teeth. J, natural habitat and living adult.