in Synaptida, [576];
in Antedon rosacea, [582];
in Cystoidea, [597] f.;
in Blastoidea, [600]
Respiratory tree, of Holothuria nigra, [563];
of Holothuroidea, [569];
of Aspidochirota, [569];
of Dendrochirota, [569], [572];
of Molpadiida, [569];
represented by caecum of Elasipoda, [569];