"Maps are given showing the total number of species per sample and the total number of specimens per 100 gm. The distribution patterns that emerged, notably the fact that Bryozoa are virtually absent from the entire fluviomarine fan, suggest that the rate of deposition is a major controlling factor in the distribution of these sessile organisms. A second set of maps illustrates the percentage distribution of several selected species in the area. Finally, the various assemblages are analysed in terms of zoarial form. The results are applied to a 58 m. deep core hole, situated near the mouth of the Grand Rhone distributary, which revealed almost the entire late Pleistocene-Recent deltaic marine sedimentary record.