Fig. 1
From: Life in a tube: morphology of the ctenostome bryozoan Hypophorella expansa
General overview of the boring ctenostome Hypophorella expansa. a, b Schematic drawing of autozooids attached to the kenozooidal stolons with retracted polypide (tentacles not shown) (a) and protruded polypide in (b). c, d, f Images of living specimens showing several morphological features when the tube layers of Chaetopterus are separated to thin sheets. e Fixed, osmified sample with the polypide stained. Abbreviations: apa – apertural area, bh – borehole, ca – cardia, cae – caecum, cg – cerebral ganglion, fg – foregut, fuc – funicular cord, gt – teeth of the gnawing apparatus, gwa – gnawing apparatus, int – intestine, l –lophophore, lb. –lophophoral base, pm – parietal muscles, pp. – pore plate, py – pylorus, rm. – retractor muscles, sbo – space balloon, sc – stolonal capsule, som – stolonal transverse muscle, st – stolon, v – vestibulum, zob – zooidal buds