Peridinium furca Ceratium furca is a species of marine dinoflagellates.

[1] This species has a straight body which is 70-200 μm long and 30-50 μm wide, with the epitheca gradually tapering into an anterior horn.

C. furca has long spines, and is an "armoured" species with a theca of thick cellulose plates.

The cells are nearly flat, with the ventral side concave and the dorsal side being convex.

[2] Ceratium furca is found worldwide.