Definition of "peristome" []

• Botany A fringe of toothlike appendages surrounding the mouth of a moss capsule. (noun)
• Zoology The area or parts around the mouth in certain invertebrates. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The peristome is short and stretches around the front end of the animal."
• "Upon the left edge of the peristome is a high, undulating membrane, sail-like in appearance when extended."
• "The peristome is a small groove leading from the anterior end to the mouth about midway down the ventral side of the body."