in Antedon rosacea, [619]

Hydroctena salenskii, [423], [424]

Hydrolaridae, [273]

Hydrophyllium, [297], [300]

Hydrorhiza, [262]

Hydrosome, [250], [251]

Hydrospire, of Blastoidea, [580], [599];

of Codaster, [599];

of Pentremites, [599];

of Granatocrinus, [599] f.