Depastridae, [320], [321]

Depastrum cyathiforme, [321]

Depressor muscles of compasses of Echinus esculentus, [527]

Dercitus bucklandi, [221]

Dermal, gill—see Papula;

membrane, [170]

Dermalia, [201]

Dermasterias, [471]

Desma (the megasclere which forms the characteristic skeletal network of the Lithistida, an irregular branched spicule), [215], [224]

Desmacella, [224]