Macrochlamys petrosa (Hutton, 1834)

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

Macrochlamys petrosa (Hutton, 1834) .

Figures 11I , 32D , 34D , 35B , 36G–I , 37C–D

Material examined. India: AM C205305 (two specimens dissected, one radula examined), Gobra Gorasthan, South Calcutta .

Description. External morphology: Shell 5.2 whorls, pale golden, glossy, spire and apex slightly raised. Protoconch smooth; teleoconch sculptured with microscopic spiral grooves. Whorl profile rounded above and below evenly convex periphery. Internal walls of early whorls complete; umbilicus open, narrow U-shape. Animal ( Figure 35B ) pale yellow-brown. Mantle laps very small, narrow, finger-shaped, not fused, uniform in colour. Right and median mantle lobes small, left mantle lobe very small. Sole of foot tripartite; caudal apparatus as for family; caudal horn large; caudal foss diamond-shaped slit in tail.

Mantle cavity ( Figure 32D ): As for family. Mantle with visible minor blood vessels, pigmentation absent, mantle gland absent.

Genital system ( Figures 34D , 36C–D ): As for family. Carrefour and talon both not embedded in albumen gland. Free oviduct short; capsular gland present; internal longitudinal pilasters absent but irregular thickenings present. Bursa copulatrix inserted on vagina, moderately short, about half spermoviduct length; duct of bursa copulatrix wide, distinguishable from bursa copulatrix, internally smooth. Vagina short, internally with longitudinal pilasters. Stimulator inserted on vagina, papilla present, dart absent, apical glands encased in stimulator sheath. Penis short, thin; epiphallus enters penis through simple pore; penis internally smooth, four to six longitudinal penis pilasters present, penial diverticulum absent. Penial sheath present, enclosing only penis; penis retractor muscle attached to base of epiphallic caecum. Epiphallus slightly longer than penis, internally smooth. Epiphallic retractor caecum moderate in size, positioned at penis-epiphallus junction, containing longitudinal pilasters. Flagellum present; flagellum and distal part of epiphallus without internal cryptae and externally smooth and slender. Spermatophore soft capsule with firm tail pipe open at one end; tail pipe long, sculptured with short branching spines.

Radula ( Figure 36G–I ): Relatively long and narrow. Central tooth with small ectocones; mesocone lanceolate, slightly 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 the mesocone, not subdivided into extra teeth. Radular formula (43.13.1.13.43) (number of rows not recorded).

Remarks. Macrochlamys is distributed in central, south and southeast Asia and contains at least 120 species, subspecies and forms ( Schileyko 2003a). In the phylogenetic analysis it grouped with Macrochlamys stumpfii , and the two taxa grouped with other members of Ariophantidae ( Figures 1–3 ). The molecular phylogenetic analysis of Hyman et al. (2007) included only a single ariophantid, Macrochlamys sp. , which was found to be the sister group of Helicarionidae .

Figures

FIGURE 1. Majority-rule consensus tree (1,743 trees, length 117 steps) from the morphological analysis containing representatives of all groups. Families and subfamilies are shaded and are labelled in bold if the group is not monophyletic.

FIGURE 2. Majority-rule consensus tree (646 trees, length 106 steps) from the morphological analysis with Dyakiidae and Urocyclidae excluded. Families and subfamilies are shaded and are labelled in bold if the group is not monophyletic.

FIGURE 3. Majority-rule consensus tree (770 trees, length 117 steps) resulting from the morphological analysis with two additional mantle lobe characters. Families and subfamilies are shaded and are labelled in bold if the group is not monophyletic.

FIGURE 11. Nervous systems. Cerebral commissure cut (cut regions shaded with diagonal lines). A. Helicarion cuvieri, AM C424333. B. Brevisentis atratus, AM C205294. C. Stanisicarion freycineti, AM C391188. D. Nitor circumcincta, AM C365822. E. Tarocystis responsivus, AM C425327. F. New Caledonian species NC3, MNHN no registration number. G. Ctenophila caldwelli, AM C205301. H. Madagascan species MA1, AM C205304. I. Macrochlamys petrosa, AM C205305. J. Everettia sp., BMNH 20020188. K. Coneuplecta pampini, AM C438751. L. Lamprocystis guttula, FMNH 174940. M. Trochomorpha rubens, FMNH 175247. Scale bars 1 mm except for J (scale bar 2 mm). Abbreviations: ce, cerebral ganglion; pa, parietal ganglion; pe, pedal ganglion; pl, pleural ganglion; vg, visceral ganglion.

FIGURE 32. Mantle cavities. A. Caldwellia imperfecta, AM C205300. B. Madagascan species MA1, AM C205304. C. Sheldonia poeppigii, NMSA V9710. D. Macrochlamys petrosa, AM C205303. E. Parmarion martensi, BPBM 252738. Scale bars 2 mm (A–B, E), 3 mm (C), 5 mm (D). Abbreviations: dg, digestive gland; i, intestine; k, kidney; mc, mantle collar; pc, pericardium; pn, pneumostome; pv, pulmonary vein; ur1, primary ureter; ur2, secondary ureter.

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 35. External morphology of caudal regions. A. Kalidos balstoni, AM C205303. B. Macrochlamys petrosa, AM C205303. C. Everettia sp., BMNH 20020188. D. Greenwoodoconcha nux, AM C433375. E. Videna planorbis, FMNH 160957. F. Dendrotrochus eva eva, FMNH 160957. Scale bars 1 mm (D), 2 mm (E–F), 5 mm (A–C).

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).

FIGURE 37. Spermatophores. SEM. A, B. Elisolimax flavescens, NMSA L5563. C, D. Macrochlamys petrosa, AM C205305. E, F. Orpiella concavum, BMNH no registration number. Scale bars 0.2 mm (D, F), 0.5 mm (B), 1 mm (A, C, E).