Lacunastrum

綠藻門Chlorophyta

綠藻綱Chlorophyceae

環藻目Sphaeropleales

水網藻科 Hydrodictyaceae

----藻屬Lacunastrum

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).