The peristomium is the second body segment in an annelid worm`s body in the anterior end. It is directly behind the prostomium and contains the mouth, tentacular cirri, and sometimes feeding palps, which may instead occur on the prostomium. If an eversible pharynx is present, it is contained in this segment as well, and can fill up to 20 segments....
• (n.) Same as Peristome.
The first segment of the earthworm`s body; contains the mouth.
Per`i·sto'mi·um noun [ New Latin ] Same as Peristome .