Gonyostomum (go-knee-os-toe-um) is a raphidophyte stramenopile. There are typically two flagella inserting subapically, one projecting forwards in swimming cells, the other trailing. With many discoidal plastids, with chlorophylls a and c, but in this genus the plastids look as green as those of chlorophytes and euglenids. Common in acidic freshwater habitats such as bogs. Free swimming specimen of Gonyostomum latum in which the anterior flagellum projects forward. Measuring 40 microns. Differential interference contrast. Differential interference contrast.