For ten points, name this phylum including sea lilies, sand dollars, sea urchins, and starfish.
Members of this phylum undergo respiration and waste removal by means of skin gills, and their water vascular system radiates from a ring canal, through which water enters via a madreporite. As adults, their nervous systems consist only of nerve rings, and from their center extend ampulla-containing tube feet, a major portion of their five-fold radial symmetry. For ten points, name this phylum including sea lilies, sand dollars, sea urchins, and starfish.
Members of this phylum undergo respiration and waste removal by means of skin gills, and their water vascular system radiates from a ring canal, through which water enters via a madreporite.
{echinodermata} (or {echinoderm}s)