SUMMARYAn entirely free‐growing variety ofPelvetia canaliculata, has been described, whose presence has been shown to be beneficial toSalicornia europea, probably acting as a surface mulch; as well as an embedded variety of less common occurrence. The receptacles of the spiralFucus, found as early as 1778 by Hudson, have been described, and from their nature the deduction drawn that thisFucusis not derived from the same species as the almost identicalF. lutariusof Sauvageau. A variety of thisFucus, of slightly different habit, has also been described. The zoning, observed at Blakeney, between the free‐growingPelvetiaand the embeddedFucusis a point of interest.In conclusion, I have to thank Prof. F. W. Oliver for placing in my hands information and notes on the Blakeney and Southampton Fucoids. I should like to offer my sincere thanks to Prof. Sauvageau for the many valuable specimens with which he supplied me, and to Mr. A. Gepp for giving me the opportunity of examining the herbarium specimens of Hudson and Turner in the British Museum, and much information about the algse in question; also my father and brother for the time and trouble they took in obtaining some of the photographs reproduced.Text‐figures 3&4 are from drawings by Miss M. Green, the others by the a