1. Bedini, C., E. Ferrero, andA. Lanfranchi, 1973: The ultrastructure of ciliary sensory cells in two turbellariaAcoela. Tiss. Cell.5, 359?372.
2. Bowen, I. D., andT. A. Ryder, 1973: The fine structure of the planarianPolycelis tenuis (Iijima), I: The Pharynx. Protoplasma78, 223?241.
3. - - 1974: The fine structure of the planarianPolycelis tenuis (Iijima), IV: Autolysis in the parenchyma and cellular replacement (in preparation).
4. Gibbons, I., andA. V. Grimstone, 1970: On flagellar structures in certain flagellates. J. biophys. biochem. Cytol.I, 697?716.
5. Kishida, Y., 1967: Electron microscopic studies on the planarian eye. 1. Fine structures of the normal eye. Sci. Rep. Kanazawa Univ.12, 75?110.