Leptochiton matthewsianus (Bednall in Bednall & Matthews, 1906 )

Sirenko, Boris, 2020, New Zealand and Australian species of the genus Leptochiton (Mollusca Polyplacophora), Zootaxa 4851 (3), pp. 401-449 : 426

Leptochiton matthewsianus (Bednall in Bednall & Matthews, 1906)

( Figures 28–31 )

Lepidopleurus matthewsi Tate & May, 1901: 412 (nom. nudum).

Lepidopleurus matthewsianus ; Bednall in Bednall & Matthews 1906: 92, pl. 9, figs. 1, la–f; Ashby 1923: 218, pl. 16, figs. 5, 5a; 1927: 93; Ashby & Cotton1930: 58.

Lepidopleurus niger Torr, 1911: 105 , pl. 225, figs. 5a–f; Ashby 1923: 220, pl. 16, fig. 4.

Terenochiton erratus Hull, 1923: 159 , pl. 24, figs. 6–9; Iredale & Hull 1925: 341, pl. 39, figs. 7–10.

Terenochiton matthewsianus ; May 1923: pl. 14, fig. 3; Iredale & Hull 1925: 341, pl. 39, fig. 3; Cotton 1964: 18, figs. 6–7.

Terenochiton niger ; Iredale & Hull 1925: 341; Cotton & Weeding 1939: 182; Cotton 1964: 18, fig. 8.

Leptochiton (Leptochiton) mattewsianus ; Kaas & Van Belle 1985: 137, fig. 61, map 21; Gowlett-Holms 2001: 74.

Type material. Neotype ( SAMA D13734). Designated by Cotton& Godfrey (1940)

Type locality. South Australia, Gulf St Vincent, Marino .

Material examined. Northern coast of Tasmania, East Devonport, between Mersey River Mouth and Pardoe Beach, bottom of stones embedded in sand near zero tide level, 2 spms ( ZISP 2379), BL 5.0–6.0 mm, 12/ 1982, leg. J. R. Penprase (sent to ZISP).

Distribution. The species was found along the southern coast of Australia, from Victoria to Albany, Western Australia; also along the northern coast of Tasmania.

Remarks. The studied specimen (BL 6.0 mm) has a 2.2 mm long radula with ca. 70 transverse rows of mature teeth. The specimen is characterized by having low, rounded valves, an antemucronal area that is longer than the postmucronal area, about 38–44 rows longitudinal rows of granules in the central areas of the intermediate valves and about 45 rows of granules in the antemucronal area of tail valve, radial rows of granules in the other areas, seven aesthetes in each tegmental granule, bent, pointed dorsal girdle scales with 12 sharp and narrow, sometimes double ribs, the central teeth of radula long and narrow, major lateral teeth with long, narrow unidentate pointed cusps.

Figures

FIGURE 28. Leptochiton matthewsianus, Northern coast of Tasmania, East Devonport, between Mersey River Mouth and Pardoe Beach, BL 6.0 mm, (ZISP 2379). A. Valve I, dorsal view; B. Valve V, dorsal view; C. Valve VIII, dorsal view; D. Valve V, tegmentum sculpture in central area; E. Valve V, rostral view; F. Valve VIII, lateral view.

FIGURE 29. Leptochiton matthewsianus, Northern coast of Tasmania, East Devonport, between Mersey River Mouth and Pardoe Beach, BL 6.0 mm, (ZISP 2379). A, C. Dorsal and ventral scales and marginal spicules and needles; B. Dorsal scales near suture; D. Dorsal scales and sutural needles.

FIGURE 30. Leptochiton matthewsianus, Northern coast of Tasmania, East Devonport, between Mersey River Mouth and Pardoe Beach, BL 6.0 mm, (ZISP 2379). A. Dorsal and ventral scales and marginal spicules and needles; B. Head of major lateral tooth of radula; C. Central portion of radula from anterior part.

FIGURE 31. Leptochiton matthewsianus, Northern coast of Tasmania, East Devonport, between Mersey River Mouth and Pardoe Beach, BL 6.0 mm, (ZISP 2379). A. Sutural needle; B. Dorsal scales; C. Marginal needle; D. Marginal spicule; E. Ventral scale near margin; F. Ventral scale from mid-girdle; G. Central and first lateral teeth; H. Heads of major lateral teeth; I. Aesthete group in central area. Scale bar 50 μm (A–H).