Fig. 3

Schematic drawing of a retracted zooid of Monobryozoon ambulans. a—anus, am—apertural muscles, b—bud, ba—basal appendage, cae—caecum, db—duplicature band, fg—foregut, int—intestine, l—lophophore, o—orifice, os—orificial sphincter, py—pylorus, rm—retractor muscles, ts—tentacle sheath, v—vestibulum