A type of tissue found in members of this phylum, containing collagen fibrils embedded in a proteoglycan hydrogel, may be altered mechanically by the protein tensilin. Nervous control, rather than muscular control, changes the mechanical properties of catch connective tissue in this phylum. Unusually for this phylum, the oral surface features many ciliated funnels, instead of a sieve-like structure, in (*) crinoids. In some members of this phylum, coelomocytes are produced by Tiedemann’s bodies. Organisms in this phylum filter water through the (-5[1])madreporite, (10[1])connected to the stone canal. The regenerative capacity of organisms in this phylum frustrated early efforts to control crown-of-thorns populations. Members of this phylum use the water vascular system to operate their tube feet, and most display five-point radial symmetry. For 10 points, (10[1])name this phylum whose members include sea cucumbers, sea urchins and starfish. ■END■ (10[1])