Key to species of the genus Fogedia 1a Cells are heterovalvate .............................................................................................................................................. F. heterovalvata 1b Cells are not heterovalvate .................................................................................................................................................................2 2a Valves with lateral area.......................................................................................................................................................................3 2a Valves without lateral area..................................................................................................................................................................9 3a Central area with stauros-like transverse expansion ..........................................................................................................................4 3b Central area without transverse expansion .........................................................................................................................................5 4a Striae 16-18 in 10 μm ............................................................................................................................................................. F. acuta 4b Striae 9-13, Areolae 35-40 in 10 μm ............................................................................................................................. F. finmarchica 4c Striae 10-12, Areolae 26-29 in 10 μm .............................................................................................................................. F. krammeri 5a External terminal raphe fissure hooked..............................................................................................................................................6 5b External terminal raphe fissure simple or slightly bent......................................................................................................................8 6a Areolae 26-29 in 10 μm............................................................................................................................................................. F. lyra 6b Areolae 35-40 in 10 μm......................................................................................................................................................................7 7a Valves 15.5-18.5 μm long, 6.5-7 μm wide .................................................................................................................. F. christensenii 7b Valves 26-37 μm long, 8-9 μm wide ............................................................................................................................... F. giffeniana 8a Striae parallel in the middle of the valve................................................................................................ F. giffeniana var. yemenitica 8b Striae radiate in the middle of the valve.......................................................................................................................... F. geisslerae 9a Valves elliptic with broad apices ........................................................................................................................................ F. elliptica 9b Valves with distinctively protracted apices ......................................................................................................................................10 10a Striae parallel in the middle of the valve.......................................................................................................................... F. orientalis 10b Striae radiate in the middle of the valve...........................................................................................................................................11 11a Striae 12-14, Areolae 15 in 10 μm...................................................................................................................................... F. coreana 11b Striae 18-21, Areolae 21-24 in 10 μm .................................................................................................................................... F. densa

Published as part of Kim, Hyesuk, Khim, Jong Seong, Witkowski, Andrzej & Park, Jinsoon, 2022, A new species of Fogedia (Bacillariophyceae) from tidal flats of Northeast Asia, pp. 77-84 in Phytotaxa 554 (1) on pages 82-83, DOI: 10.11646/phytotaxa.554.1.6, http://zenodo.org/record/6809823