Radial ossicle—see Radial Plate
Radial perihaemal canal, of Asterias rubens, [448];
of Ophiothrix fragilis, [488];
of Echinus esculentus, [518], [524];
of Holothuria nigra, [566]
Radial plate, of Ophiothrix fragilis, [484];
of Cladophiurae, [500];
of calcareous ring in Holothuria nigra, [566];
in Holothuroidea, [567], [569];
in Elasipoda, [569];