Amalda monilifera (Reeve, 1864)

Figs 19 F–G, 20B, E

Ancillaria monilifera Reeve, 1864: pl. 10, sp. 36.

Gracilispira monilifera – Wilson 1994: 131, pl. 29, fig. 16 a–c.

Amalda (Gracilispira) monilifera – Gratecap 2016a: 6, 18, fig. 12.

Type material

Holotype (by monotypy)

WESTERN AUSTRALIA • Swan River; NHMUK 197933.

Material examined

One sequenced specimen (Table 1).

Description

MEASUREMENTS. Shell small (SL up to 18 mm).

SHELL. Ovate-fusiform, with conical spire with nearly straight sides. Primary spire callus thin, semitransparent, smooth, covering all whorls, except protoconch. Protoconch rounded above, boundary with teleoconch indistinct, first whorl diameter 0.65 mm. Secondary callus medium thick on parietal wall and forming distinct parietal pad, extending only to penultimate whorl. Plication plate with 3 weak ridges and still two weaker on columella. Olivoid groove distinct but shallow, labral denticle prominent, narrow triangular. Upper anterior band weakly convex, with low median ridge, lower anterior band nearly flat, smooth. Colour of primary callus light orange, body whorl cloak creamy with light brown anastomosing pattern, subsuturally a row of large, irregular oval brown spots, seen through transparent callus on all teleoconch whorls, olivoid band and lower anterior band with row of brown spots, plication plate creamy.

RADULA (n= 1, Fig. 20B, E). With broad, subtriangular lateral teeth with sharp, hook-shaped, curved tip. Central cusp multicuspid, with three major central cusps, median much narrower and slightly shorter than lateral ones, in addition medium long, irregularly shaped, 2–4 cusps between lateral and median cusps, also irregular-shaped fissures in median part of central tooth. Lateral flaps of central tooth dentated, with 3–5 triangular short cusplets.

Remarks

The radula of the species is studied here for the first time.

Ninomiya (1990) included this species in his new subgenus Mundaspira (type species Amalda concinna Ninomiya, 1990).

Distribution

The Recherche Archipelago in southern Western Australia (Gratecap 2016a), in 0– 15 m.