Pseudoproct

The pseudostome and pseudoproct become obscure and are shortly obliterated, the sarcoid forming a thick, smooth, uniform layer over the stem and over its terminal disk.

The pseudembryo moves rapidly in the water, rolling round and swinging from side to side ; as a rule, and especially when at rest, the surface bearing the pseudostome and pseudoproct is turned downwards.

The pseudembryo or echinopzrdium, at first cilisted and spheroidal, becomes after a time wedge-shaped; at its broad end appears the mouth or psaudostome, and at the other the anus or pseudoproct.

The larva now fixes itself by the 'pseudoproct.'