Sentence:  The sarcodic body of the pseudembryo begins to shrink, the <WSD>pseudostome</WSD> and the two lower bauds of cilia disappear, and afterwards the two upper bands, and the embryo then becomes fixed to a stone, seaweed, or some other object. 
Meaning of the word marked with <WSD> tags:  The oral opening on the pseudembryo of an echinoderm.