4. Cocconeis conspicua A. Schmidt (Figs 87, 105)

Basionym: Schmidt et al. 1894b, pl. 196, figs 27–30.

Description: Valves broadly elliptical, but slightly oblique along apical axis, 31–38 μm long, 24–30 μm wide. SV: sternum broadly elliptical and sigmoid. Longitudinal hyaline area bisecting twice striae between sternum and valve margins, a row of very large puncta on the outer hyaline area, the largest punctum in the area 1.5 μm in diameter. A longitudinal line crossing striae between the sternum and inner hyaline area. Transapical striae radiate towards the apices, 26–27 in 10 μm, striae composed of elongated areolae. RV: No RV observed, only trace of sigmoid raphe could be seen.

Remarks: This taxon is characterized by a marginal axial hyaline area on each part of the SV and the presence of large round structures in these hyaline areas. There are no descriptions of this taxon except for the illustrations at the times of the naming. From the original valve drawings (Fig. 92) of Schmidt et al. (1894b), valves are 27–38 μm long and 18–29 μm wide. At that times, it was found in Kings Mill Islands (now Gilbert Islands) and Samoa in the Pacific Ocean, in Bissex of Barbados in the West Indies, and in Singapore (Schmidt et al. 1894b). However, it is placed on the checklist of marine diatoms in the Caribbean Sea (Navarro and Hernández-Becerril, 1997). Based on the localities found to date, it is a typical tropical taxon. Very rare in a few samples as epiphytes on seaweed in rock pools (St. 2) of Seogwipo coast; it is herein newly described for South Korea.