Fig. 5

3D reconstruction of serial semithin sections of the lophophoral base of Stephanella hina. Nervous system in yellow, epistome in orange and coelomic cavity in blue. a Oral view of the lophophoral base showing the epistome above the cerebral ganglion. Note that the inner lophophoral arc (forked canals) is not fused (asterisk). b Oblique view of the lophophoral base with the epistome displayed transparently. c Schematic drawing of the three coelomic canals, the forked canal and the epistome canal on the anal side and the ring canal on the oral side. d Lateral view of the epistome including the muscles traversing its cavity. Abbreviations: cg - cerebral ganglion, con - circumoral nerve ring, ec – epistomial coelom, em – epistome muscles, ep - epistome, fc – forked canal, gh - ganglionic horn, mo - mouth opening, ot - oral tentacles, rc – ring canal, rn - radial nerve