Trepang, [571]

Treponema, [111], [121];

T. obermeieri, [121];

T. pallidum, [121];

T. zeemannii, [120]

Triaene, [183], [224], [233]

Triaxon, [184]

Trichaster, [501]

Trichasteridae, [501]

Trichites (hair-like spicules often occurring in sheaves or clusters), [234]