(4807) DEJOUX, C. & L. SAINT-JEAN, 1972. £tude des communautes d’invertebres d’herbiers du Lac Tchad: recherches preliminaires. Cah. O.R.S.T.O.M. (Hydrobiol.) 6(1): 67-83. (With Engl, s.). — (Lab. Hydrobiol, O.R.S.T.O.M., B.P. 1434, Bouake, Ivory Coast), A new device for the collecting of plant samples from a constant volume is described, and a preliminary characterization of the invertebrate fauna associated with aquatic vegetation in the Tchad Lake is presented. References are made to "Agrionidae” and Libellulidae.