Sesara infrendens (Gould, 1844)

Hyman, Isabel T. & Ponder, Winston F., 2010, A morphological phylogenetic analysis and generic revision of Australian Helicarionidae (Gastropoda: Pulmonata: Stylommatophora), and an assessment of the relationships of the family 2462, Zootaxa 2462 (1), pp. 1-148 : 98-99

Sesara infrendens (Gould, 1844)

Figure 34E , 36J–L

Material examined. BMNH 1995067 (one specimen dissected, radula examined). Locality unknown. Godwin-Austen collection No. 161 .

Description. External morphology: Shell 6.5 whorls, light orange-brown, spire and apex raised. Protoconch sculptured with very fine radial lirae; teleoconch with radial ribs; microradials present between ribs. Whorl profile flattened above and below evenly convex periphery. Internal walls of early whorls complete; umbilicus closed. Animal light yellowish brown. Mantle laps and lobes not examined due to extreme contraction of animal. Sole of foot tripartite; caudal apparatus as for family; caudal horn medium; caudal foss horizontal slit in tail.

Mantle cavity: As for family. Mantle with no visible minor blood vessels, pigmentation absent.

Digestive system: Oesophageal crop absent.

Genital system ( Figure 34E ): Specimen immature; reproductive tract poorly developed. Bursa copulatrix inserted on vagina. Vagina long. Stimulator absent. Penis long; internal sculpture not examined; penial diverticulum absent. Penial sheath not examined; penis retractor muscle attached to tip of epiphallic caecum. Epiphallus longer than penis. Epiphallic retractor caecum moderate in size, positioned in middle of epiphallus, doubled over. Spermatophore not present in dissected specimen.

Radula ( Figure 36J–L ): Relatively long and narrow. Central tooth with small ectocones; mesocone lanceolate, longer than tooth base. Lateral and marginal tooth fields distinguishable. Lateral teeth with endocone smaller than central tooth ectocones; ectocone equal in size to those on central tooth; mesocone longer than tooth base. Marginal teeth with endocones absent; ectocones shorter and narrower than mesocone, not subdivided into extra teeth. Radular formula (39.10.1.10.39) × at least 45 rows.

Remarks. Sesara is found in the Hindustan Peninsula, Myanmar, Thailand and Laos and contains about 20 species ( Schileyko 2002b). It was included in Macrochlamydinae by Solem (1966), in Helicarionidae by Hausdorf (1998) and in Ariophantinae by Schileyko (2002b). The species dissected was identified in the BMNH collections as Sesara infrendens (Gould, 1844) , which was described from Burma.

Figures

FIGURE 34. Reproductive systems. A. Madagascan species MA1, AM C205304. B. Elisolimax flavescens, NMSA V9710. C. Sheldonia poeppigii, NMSA L5563. D. Macrochlamys petrosa, AM C205305. E. Sesara infrendens, BMNH 1995067. F. Parmarion martensi, BPBM 252738. Scale bars 1 mm (E), 2 mm (A), 5 mm (B–D, F). Abbreviations: alb, albumen gland; bc, bursa copulatrix; c, caecum; ep, epiphallus; fl, flagellum; fov, free oviduct; her, hermaphrodite duct; ls, lime-sac; m, muscle attaching penial sheath to epiphallus (only shown in E); ov, ovotestis; p, penis; pr, prostate; prm, penis retractor muscle; pt, penial sheath; st, stimulator; ut, uterus; v, vagina; vd, vas deferens.

FIGURE 36. Radulae. SEM. A–C. Sheldonia poeppigii, NMSA V9710. D–F. Elisolimax flavescens, NMSA L5563. G– I. Macrochlamys petrosa, AM C205305. J–L. Sesara infrendens, BMNH 1995067. M–O. Parmarion martensi, BPBM 252738. P–R. Everettia sp., BMNH 20020188. Scale bars 10 mm (G–I), 20 mm (A–F, J–R).