Scanning electron micrographs of Omanicotyle heterospina n. gen. et n. comb. a, The anterior end of the worm, showing two septate buccal suckers (thin arrow), and its delineation from the main body. A circular area of irregular folded tegument on the dorsal surface is also evident (thick arrow), the precise function of which is unknown. b, the spindle shaped, operculated eggs, each bearing a short posterior filament and a long, tangled, apical filament which may exceed 10× the length of the egg proper. c, a ciliated oncomiracidium emerging from an egg. Scale bars: a, b = 100 μm; c = 20 μm.