Gastropod gill morphology 2 
Plate 3. SEM and LM micrographs of the gill of Planaxis sulcatus. A. General dorsal view of gill filaments. Bar = 40 
pm. B. Dorsal ridge of a filament. Bar = 13 um. C. Detail of dorsal ridge. Bar = 4 um. D. General view of the 
gill in LM section. Bar = 0.2 mm. E. Longitudinal section of filaments with haemocoelic spaces (hs). Bar = 60 
um. Key: г, dorsal ridge; s, thin sheet; c, cilia; nc, non-ciliated cells; mv, microvilli; ct, connective tissue. 
