Fig. 4 in Organization of the lophophore in the deep-sea brachiopod Pelagodiscus atlanticus and evolution of the lophophore in the Brachiozoa

Fig. 4 Consecutive histological sections of the lophophoral arm of Pelagodiscus atlanticus. a Section of the distal part of the lophophoral arm (plane of the section (a) is marked on Fig. 3d): the small canal (sc) is filled with muscle cells and contains the lophophoral vessel (lv). b Section of the lophophoral arm with two profiles of large coelomic canals (lc) (plane of the section (b) is marked on Fig. 3d): the brachial retractor (br) is visible. c Section of the lophophoral arm near the mouth