Fig. 3 in Organization of the lophophore in the deep-sea brachiopod Pelagodiscus atlanticus and evolution of the lophophore in the Brachiozoa

Fig. 3 Diagrams of the Pelagodiscus atlanticus lophophore. a Lophophore with brachial axis (marked by dotted line). b Lophophore with large canals (dark gray), small canals (light gray), and a brachial retractor (cross-hatched). c Cross section through the middle of the arm. d Planes of sections of the lophophore in Fig. 4. bf brachial fold, br brachial retractor, fg food groove, it inner tentacle, lc large canal, m mouth, ot outer tentacle, rft region, where new tentacles form, pc periesophageal coelom, sc small canal, t tentacles, a plane of the section on Fig. 4a, b plane of the section on Fig. 4b, c plane of the section on Fig. 4c, d plane of the section on Fig. 4d