"Ambulacral system of a starfish. a, ampullae; ap, Polian vesicles; c, circular canal; m, madreporite; m', madreporic canal; p, tube-feet; r, radial vessels; r', branches to ampullae." -Parker, 1900

Ambulacral System

"Ambulacral system of a starfish. a, ampullae; ap, Polian vesicles; c, circular canal; m, madreporite;…

This diagram shows a portion of the water-vascular system of the starfish. a, ampullae; f, ambulacral feet; m, madreporic body; p, polian vesicles; r.c., ring canal, with the upper portion removed at the right of the figure; r.t., radical water tubes; s, stone canal.

Starfish

This diagram shows a portion of the water-vascular system of the starfish. a, ampullae; f, ambulacral…