Fig. 13 in Boring bryozoans: an investigation into the endolithic bryozoan family Penetrantiidae

Fig. 13 Histological semi thin sections through the orifice and vestibular area of four different penetrantiids. a–b Penetrantia cf. concharum from France. c–d P. concharum from Sweden. e P. parva from Northern New Zealand. f Stereomicroscopic image of an autozooid of Penetrantia sp. from Japan. g–h Penetrantia sp. from Japan. ap aperture, at atrium, bc body cavity, c collar, d diaphragm, exc exterior cuticle, ic inner cuticle, op operculum, pd parieto-diaphragmatic muscle, ped peduncle, ply polypide, pvm parieto-vestibular muscle, s septum, st stolon, t tentacle, ts tentacle sheath, v vestibulum, vl vestibular lip, vw vestibular wall