2. Aulacodiscus orientalis Greville (Fig. 9) Type locality: Ceylon. References: Schmidt et al. 1874–1959, pl. 34, figs 1–3; Williams 1988, p.15, pl. 17, figs 1–3; Lobban et al. 2012, p. 249, pl. 5, figs 3–5. Morphometrics: Valves 187 (85–140) μm, striae radiate from the center, 5 in 10 μm, areolae 3.5 in 10 μm on a stria. Thirteen pseudocelli on elevations in the corner of valve. Remarks: Aulacodiscus orientalis was reported in some places, North Celebes of Indonesia and Hawaiian Islands (Schmidt et al. 1874–1959), mangrove swamps of South Nigeria (Mills 1932), Guam in the western Pacific Ocean (Lobban et al. 2012), and the western coast of India (Sushanth and Rajashekhar 2012). This taxon is a typical one inhabiting warmer oceans. It was encountered once in this sampling areas, the Seogwipo coast, representing a new record for South Korea.

Published as part of Joh, Gyeongje, 2021, Distribution and frequent occurrence of diatom taxa (Bacillariophyta) inhabiting warmer oceans in Seogwipo coast of Jeju Island, southernmost Korea, pp. 1-67 in Phytotaxa 517 (1) on page 7, DOI: 10.11646/phytotaxa.517.1.1, http://zenodo.org/record/8061058