protractor muscles
From ZooTerms (Dictionary of Invertebrate Zoology)
Revision as of 23:29, 13 September 2013 by Andreas Plank (Talk | contribs)
contractile muscle that functions to extend an organ.
protractor muscles: 1. A
2. (NEMATA) Muscles attached to the stylet knobs or base and anteriorly to the body wall or head skeleton.
3. (Sipuncula) In adult Xenosiphon and some larval forms, an extra pair of muscles attached to the introvert near the brain and to the body wall of the trunk anteriorly.