Fig. 4

Scanning electron micrographs of the nonmetameric area of the trunk. a. Panoramic view of the nonmetameric area showing small scattered dorsal papillae (arrowheads). b. The same area at higher magnification showing cuticular plaques (squares). c. The zone of enlarged dorsal papillae and ventral ciliary band. d, g. The cuticular plaques of the nonmetameric papillae. e Enlarged papillae in dorsal view. f. The same area at higher magnification showing cuticular plaques (white arrows), openings of multicellular glands (yellow arrows) and ventral ciliary band. h. The tip of the enlarged papilla with the cuticular plaque. i. Cilia around the opening of the duct of the multicellular gland on the enlarged papilla. j. The same on the nonmetameric papilla. Abbreviations: df – dorsal furrow, dp – dorsal papilla, vcb – ventral ciliary band