|Description||Slide shows two diagrams illustrating 'the action of the Chaetopodan introvert'.|
Diagrams are labelled 'A' and 'B' and have further labels and key.
Title below image reads 'Fig 126 - diagrams to illustrate the action of the Chaetopodan introvert. (From Lang). A shows the apparatus at rest ; the mouth leads into the buccal cavity (B), with paragnaths in its wall ; P, the pharynx, with jaws at its anterior end ; c, brain ; p, protractor muscles ; r, retractors. B the pharynx has been brought forward or protruded by the eversion, or turning inside out, of the buccal region, so that the jaws (j) now lie some way infront of the head, which is represented by the brain.'