Heterothyone

Panning, 1949

4 species

Body curved, a bit swollen in the middle portion. Feet in the radii in one or two rows, in lesser numbers in the middle section of the body also in the interradii. The calcareous ring has undivided parts. The radialia are clearly lengthened to the rear, massive or forked tail variety. Cups in the upper skin, deeper in the skin, an almost closed armour of large scales; smaller plates lying on them. (Panning, 1966)