Bar = 70 um. 
B. Detail of a few filaments. Bar = 30 um. C. Detail of one filament with border area between ciliated and non- 
ciliated cells. Bar = 2 um. D. General view of the gill in LM section. Bar = 0.2 mm. E. Longitudinal section of 
filaments. Bar = 75 um. Key: г, latero-dorsal ridge; s, thin sheet; c, cilia; mc, mucous cell; hs, haemocoelic 
space. 
