Lacunastrum
綠藻門Chlorophyta
綠藻綱Chlorophyceae
環藻目Sphaeropleales
水網藻科 Hydrodictyaceae
藻屬：暫無中文名 Lacunastrum McManus, 2011
描述：Coenobia plana, multicellularia, circularia, cellulis gracilibus. Cellulae externae lobis duobus, longis et cylindraceis in planitie coenobii; lobus uterque latitudine cellulae longior. Spacia intercellulosa typice diametro cellulae grandiora; parietes cellularum typice laeves. Flat, multicellular, circular coenobia with slender cells. Outer cells with two lobes in the plane of the coenobium. Lobes are long and cylindrical, each longer than the cell is wide. Intercellular spaces typically larger than the cell diameter, cell walls typically smooth. Type: Lacunastrum gracillimum (West et G. S. West) H. McManus (P. duplex var. gracillimum 1895).