FIGURE 9 in Description of a new species of Sabellidae (Polychaeta, Annelida) from fresh and brackish waters in Europe, with some remarks on the branchial crown of Laonome

FIGURE 9. Laonome spp. Semithin section (1 µm) of the branchial crown. A–D. L. kroyeri. A. Ten pairs of separated radioles; dorsal lips, ventral lips and ventral radiolar appendages visible. Dorsal lips with blood vessel but without internal skeletal cells. B. Radioles, right and left part of ventral and dorsal lips fused with one another (250 µm basal of section A). C. Coelomic cavities of the median collar tips and those located laterally at the border of the ventral lip separated (64 µm basal of section B). D. Coelomic cavities of the median collar tips and those located laterally at the border of the merged ventral lip (41 µm basal of section C). E–H. L. triangularis. E. dorsal lips with internal skeletal cells. F. Radioles and right and left part of fused ventral lip, dorsal lips separated (77 µm basal of section E). G. Right and left part of dorsal lip fused, median part of the ventral lip fused with the collar (112 µm basal of section F). H. Coelomic cavities of the median collar tips and those located laterally at the border of the ventral lip merged; internal skeletal cells of the dorsal lips still visible (arrows; 11 µm basal of section G). Scale bars A–H 100 µm. (abbr: c collar, d dorsal, dl dorsal lip, m mouth opening, p pinnula, ra radiolus, v ventral, vl ventral lip, vra ventral radiolar appendage).