Assertion: worm's mouth | /r/AtLocation | anterior end of the animal
Facets:
Source sentences:
text: The mouth is located at the anterior end of the animal; in the class Sipunculidea, the mouth is surrounded by a mass of 18 to 24 ciliated tentacles, while in the class Phascolosomatidea, the tentacles are arranged in an arc above the mouth, surrounding the nuchal organ, also located at the tip of the introvert.