Emarginula undulata Melvill & Standen, 1903

Herbert, David G., 2024, The Vetigastropoda (Mollusca) of Walters Shoal, with descriptions of two new genera and thirty new species, European Journal of Taxonomy 923, pp. 1-119 : 16-17

Emarginula undulata Melvill & Standen, 1903

Fig. 7

Emarginula undulata Melvill & Standen, 1903: 290 , pl. 20 fig. 1.

Type loc.: Gulf of Oman (25°58′ N 56°54′ E), depth 285 m.

Emarginula vadum Barnard, 1963b: 297 , figs 23d, 24b.

Type loc.: off Cape Vidal, KwaZulu-Natal, South Africa, depth 146– 183 m.

Emarginula undulata – Thiele 1915 in 1912–1919: 75, pl. 9 figs 10–11. — Herbert & Kilburn 1986: 12, figs 2–3, 39–44. — Bosch et al. 1995: 30. — Singer 1998: 7. — Herbert 2015: 22 . — Poppe & Tagaro 2020: 44, pl. 37 figs 3–4.

Emarginula vadum – Kilburn 1978: 444, pl. 4a, e.

Material examined

WALTERS SHOAL – slopes • 1 empty shell; stn DW4877; 33°10′ S, 43°49′ E; depth 217–256 m; 1 May 2017; MNHN • 2 empty shells; stn DW4878; 33°09′ S, 43°50′ E; depth 221–256 m; 1 May 2017; MNHN • 1 empty shell; stn DW4881; 33°16′ S, 43°50′ E; depth 377–382 m; 2 May 2017; MNHN • 2 empty shells; stn DW4885; 33°17′ S, 43°55′ E; depth 272–380 m; 3 May 2017; MNHN • 1 empty shell; stn DW4897; 33°09′ S, 43°59′ E; depth 490–584 m; 5 May 2017; MNHN .

Distribution

Widely distributed along the continental margin of the western Indian Ocean, from the Gulf of Oman southwards to eastern South Africa, at depths of 50–400 m (living 75–120 m) ( Herbert 2015) and recently recorded from the Philippines ( Poppe & Tagaro 2020). Found on the slopes of Walters Shoal, at depths of 256–490 m (none collected alive).

Remarks

Emarginula undulata is a distinctive species on account of its thin shell with numerous fine, concentrically elongate intritacalx pits, raised selenizone and relatively few, broad, radial ridges with widely-spaced, conical bumps.

Figures

Fig. 7. Emarginula undulata Melvill & Standen, 1903, Walters Shoal, stn DW4878, base 6.8×4.6 mm, height 3.8 mm (MNHN).