Helicarion mastersi ( Cox, 1868 )

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 : 24-30

Helicarion mastersi ( Cox, 1868)

Figures 6A–B , 7C–D , 8C–D , 9C–D , 12B , 13B , 14C , 15A–C

Vitrina mastersi Cox, 1868: 86 , pl. 14, figs 12, 12a; Pfeiffer, 1876: 24.

Helicarion mastersi: Cox, 1909: 6 ; Iredale, 1941: 6; Pfeiffer & Clessin, 1881: 32; Tryon, 1885: 170, pl. 38, figs 48–49. Vercularion mastersi: Iredale, 1937c: 9 .

Helicarion mastersi callidus Iredale, 1941: 6 ; Smith, 1992: 234.

Helicarion mastersi mastersi: Smith, 1992: 234 .

Synonymy follows Smith (1992).

Material examined. New South Wales, Australia: Holotype: AM C101139 (one shell measured, photographed), Kiama (34º40' S, 150º51' E), pre 1868, G. Masters.

Other material: AM C101138 ( callidus holotype) (one shell measured, photographed), Twofold Bay area (37º4' S, 149º53' E), pre 1941 ; AM C334204 (three specimens dissected; one radula examined), ca. 2.6 km NW of Nadgee Beach, Nadgee R, Nadgee Homestead (37º26' S, 149º56' E), 21 May 1970, H. Recher ; AM C162824 (one specimen dissected), ca. 2.6 km NW of Nadgee Beach, Nadgee R, behind " Arry's Ut " (37º25.86' S, 149º56.2' E), 18 Jan. 1970, H. Recher ; AM C115975 (one specimen dissected), Sydney S, Royal National Park, S end Lady Carrington Drive (34º9' S, 151º1.75' E), under palm fronds, 27 May 1979, J. Stanisic .

Description. External morphology: Shell ( Figures 7C , 8C , 9C ) reduced, 3 whorls, reddish brown, shape and sculpture as for genus. Animal ( Figure 6A ) with sole white, body grey, darker at end of tail and above head. Right and left mantle laps wide at base, long, tapering to a point, not fused, uniform in colour. Right and left mantle lobes small, middle mantle lobe of medium size. Caudal horn very small.

Mantle cavity and digestive system: As for genus.

Genital system ( Figures 12B , 13B , 14C ): As for genus. Free oviduct with internal longitudinal pilasters present distal to capsular gland. Vagina very short, internally with longitudinal pilasters. Penis moderately long; penial sheath present, enclosing only penis. Epiphallus shorter than penis, simple internally. Spermatophore as for genus.

Radula ( Figure 17A–C ): As for genus. Marginal tooth ectocones equal in length to mesocone. Radular formula (65.15.1.15.65) × 122 rows.

Range and habitat. Helicarion mastersi is found in habitats ranging from rainforest to dry sclerophyll woodland in southern to mid New South Wales. It ranges from Nadgee Nature Reserve, south of Eden in southern New South Wales, to Mt. Kelgoola and Mt. Coricudgy, east of Rylstone, New South Wales, and also extends to the Australian Capital Territory in the west. This species is most commonly found under logs, rocks, litter and other debris on the ground but is also occasionally found on trees, on the trunks or the underside of leaves.

Remarks. Specimens from the extreme southern end of the range (Twofold Bay, southern New South Wales) of Helicarion mastersi were differentiated by Iredale (1941) as the subspecies Helicarion mastersi callidus on the basis of a more tightly coiled shell and dark grey body colouration in contrast to the whitish colouration seen in mastersi . A number of specimens from different parts of the range were examined and no differences in body colouration, shell coiling or anatomy were found. For this reason the subspecies have been synonymised.

The range of Helicarion mastersi does not overlap with any other Helicarion species. Helicarion nigra (Quoy and Gaimard, 1832) is found further south in Victoria and H. leopardina Iredale, 1941 occurs further to the north. Two other semislug species from the group with cryptae in the epiphallic flagellum and no caecum, Mysticarion porrectus and Peloparion iridis , overlap in range with H. mastersi , as does the semislug Fastosarion freycineti . These species can be distinguished from H. mastersi by their smaller size and different body colouration. Mysticarion porrectus has a cream body, P. iridis is grey with dark markings on the foot and around the rounded mantle laps and F. freycineti is cream with grey markings and has a less flattened shell than H. mastersi .

Figures

FIGURE 6. Live Helicarionidae. A–B. Helicarion mastersi, AM C399075. Whole animal (A); close-up of caudal region (B) (arrow shows caudal mucous plug). C. Eggs of Mysticarion porrectus, AM C421841. D. Parmavitrina megastoma, AM C377461. E. Parmavitrina sp., AM C398947. F. Peloparion iridis, AM C161946. G. Peloparion iridis, Mt. Ravensbourne. H–I. Fastosarion superba. J. Stanisicarion freycineti, AM C391188. K. Stanisicarion virens. L. Eungarion mcdonaldi. M. Eggs of Eungarion mcdonaldi. N. Parmacochlea fischeri, AM C106767. Photographs by A. Miller (A–C, E, J), M. Shea (D), W. Rudman (F), F. Millen (N), all copyright Australian Museum; photographer unknown, copyright Queensland Museum (G–I, K–M).

FIGURE 7. Shells, dorsal view. A. Helicarion cuvieri, AM C443929. B. Helicarion cuvieri, BMNH 197780 (S of Vitrina verrauxii). C. Helicarion mastersi, AM C101139 (H). D. Helicarion mastersi, AM C101138 (PRH of H. mastersi callidus). E. Mysticarion insuetus, AM C113776 (S). F. Mysticarion porrectus, AM C101136 (PRH). G. Mysticarion hyalina, BMNH 1983075 (H). H. Parmavitrina planilabris, AM C103630. I. Peloparion helenae, AM C101142 (H). J. Brevisentis jacksoniensis, BMNH not registered (S). K. Brevisentis jacksoniensis, AM C101143 (H of B. exclusus). L. Fastosarion superba, BMNH not registered (POS). Scale bars 3 mm (G, I–K), 5 mm (A–F, H), 10 mm (L). Photographs by M. Allan (D, I), H. Barlow (A, C, H), D. Beechey (E–F, K), W. Ponder (B, G, J, L). Abbreviations: H, holotype; POS, possible syntype; PRH, probable holotype; S, syntype.

FIGURE 8. Shells, lateral view. A. Helicarion cuvieri, AM C443929. B. Helicarion cuvieri, BMNH 197780 (S of Vitrina verrauxii). C. Helicarion mastersi, AM C101139 (H). D. Helicarion mastersi, AM C101138 (PRH of H. mastersi callidus). E. Mysticarion insuetus, AM C113776 (S). F. Mysticarion porrectus, AM C101136 (PRH). G. Mysticarion hyalina, BMNH 1983075 (H). H. Parmavitrina planilabris, AM C103630. I. Peloparion helenae, AM C101142 (H). J. Brevisentis jacksoniensis, BMNH not registered (S). K. Brevisentis jacksoniensis, AM C101143 (H of B. exclusus). L. Fastosarion superba, BMNH not registered (POS). Scale bars 3 mm (E–G, I–K), 5 mm (A–D, H), 10 mm (L). Photographs by H. Barlow (A, C–D, G–H, L), D. Beechey (E, J), W. Ponder (B, F, I, K). Abbreviations: H, holotype; POS, possible syntype; PRH, probable holotype; S, syntype.

FIGURE 9. Shells, ventral view. A. Helicarion cuvieri, AM C443929. B. Helicarion cuvieri, BMNH 197780 (S of Vitrina verrauxii). C. Helicarion mastersi, AM C101139 (H). D. Helicarion mastersi, AM C101138 (PRH of H. mastersi callidus). E. Mysticarion insuetus, AM C113776 (S). F. Mysticarion porrectus, AM C101136 (PRH). G. Mysticarion hyalina, BMNH 1983075 (H). H. Parmavitrina planilabris, AM C103630. I. Peloparion helenae, AM C101142 (H). J. Brevisentis jacksoniensis, BMNH not registered (S). K. Brevisentis jacksoniensis, AM C101143 (H of B. exclusus). L. Fastosarion superba, BMNH not registered (POS). Scale bars 3 mm (D–G, I–K), 5 mm (A–C, H), 10 mm (L). Photographs by H. Barlow (A, C–D, H–I), D. Beechey (F, K), W. Ponder (B, E, G, J, L). Abbreviations: H, holotype; POS, possible syntype; PRH, probable holotype; S, syntype.

FIGURE 12. Reproductive systems. A. Helicarion cuvieri, AM C424333. B. Helicarion mastersi, AM C334204. C. Mysticarion porrectus, AM C205296. D. Mysticarion hyalina, AM C128630. E. Parmavitrina planilabris, AM C334357. F. Peloparion helenae, AM C205295. G. Brevisentis jacksoniensis, AM C348670. H. Brevisentis jacksoniensis, AM C205293. I. Fastosarion superba, AM C425248. Scale bars 2 mm (C–D, F–H), 5 mm (A–B, E, I). Abbreviations: alb, albumen gland; bc, bursa copulatrix; c, caecum; ep, epiphallus; fl, flagellum; fov, free oviduct; her, hermaphrodite duct; m, muscle attaching penial sheath to epiphallus (only shown in E); ov, ovotestis; p, penis; pr, prostate; prm, penis retractor muscle; pt, penial sheath; ut, uterus; v, vagina; vd, vas deferens.

FIGURE 13. Penis interiors. A. Helicarion cuvieri, AM C424333. B. Helicarion mastersi, AM C334204. C. Mysticarion porrectus, AM C205296. D. Mysticarion hyalina, AM C128630. E. Parmavitrina planilabris, AM C334357. F. Peloparion helenae, AM C205295. G. Brevisentis jacksoniensis, AM C205293. H. Fastosarion superba, AM C425248. I. Stanisicarion freycineti, AM C391188. J. Stanisicarion virens, QMMO19238. K. Eungarion mcdonaldi, AM C438760. L. Parmacochlea fischeri, AM C441743. Scale bars 1 mm (A–D, F–G I, K–L), 2 mm (E, H, J). Abbreviations: c, caecum; ep, epiphallus; fl, flagellum; p, penis; pp, penial pilaster; ppu, penial pustules; prm, penis retractor muscle; pt, penial sheath; pv, penial verge; vd, vas deferens.

FIGURE 14. Spermatophores. SEM. A, B. Helicarion cuvieri, AM C424333. C. Helicarion mastersi, AM C334204. D. Brevisentis jacksoniensis, AM C205293. E, F. Eungarion mcdonaldi, AM C438760. G, H. Nitor wiangariensis, AM C334361. Scale bars 0.1 mm (F), 0.2 mm (H), 0.5 mm (B, C, G), 1 mm (A, D, E).

FIGURE 15. Radulae. SEM. A–C Helicarion mastersi, AM C334204. D–F. Mysticarion porrectus, QMMO29298. G–I. Mysticarion hyalina, AM C128630. J–L. Parmavitrina planilabris, AM C334357. M–O. Peloparion helenae, AM C205295. P–R. Brevisentis jacksoniensis, AM C205293. Scale bars 20 mm (A–I, M–R); 50 mm (J–L).

FIGURE 17. Radulae. SEM. A–C. Fastosarion superba, AM C425248. D–F. Stanisicarion freycineti, AM C391188. G– I. Parmacochlea fischeri, AM C441743. J–L. Nitor circumcincta, AM C356607. M–O. Pravonitor kreffti, AM C425415. P–R. Expocystis rustica, AM C425540. Scale bars 20 mm (D–R), 50 mm (A–C).