Fig. 3

General anatomy of the anterior end of adult Terebella lapidaria (Linnaeus 1767), 5 μm sections, Azan-staining, light microscopic images. A. Cross-section through anterior head region from which tentacles and branchiae emerge. B. Cross-section through middle head region. C. Cross-section through posterior head region, cc united to the vnc and anterior oesophageal cavity is identifiable. D. Close-up of the cross-section through the lateral origin of buccal tentacles. E. Close-up of the cross-section of the dorsal origin of the branchiae. F. Close-up of the cross-section through tentacles and branchiae. G. Close-up of the cross-section through the ventral nerve cord, huge glandular epidermal cells and the subepidermal vnc are shown. br – branchiae; bv – blood vessel; cc – circumoesophageal connectives; ch – chaete; cs – cell soma; ep – epidermis; ln – lateral nerve; oe – oesophagus; ph – pharynx; te – buccal tentacles; tn – tentacular nerves; vnc – ventral nerve cord