Transverse flagellum and groove, in Dinoflagellata, [110], [130] f.;

multiple, in Polykrikos, [132]

Transverse (= tentacular) plane, [414]

Transverse section, of the arm of an Asteroid, [443];

of the arm of an Ophiuroid, [480];

of the radius of an Echinoid, [518];

of the radius of a Holothuroid, [562];

of body of a Holothuroid, [563];

of arm of Antedon, [586]

Trembley, [254], [255]