of E. elegans, [510];

of Echinarachnius parma, [544]

Trifoliate pedicellariae, of Echinus esculentus, [507], [508];

of E. acutus, [509];

of E. alexandri, [510];

of Echinocardium cordatum, [550];

absent in Cidaridae, [534]

Trigonocidaris arbacina, [539]

Triloculina, [59], [66]

Trimastigidae, [111], [112]