A pedunculate cirripede from the Upper Silurian of Oesel Esthonia

THE discovery of a pedunculate cirripede in Silurian rocks carries the history of that order a long way back; for until now the earliest record of a pedunculate is from the Rhætic, and that of the goose-barnacles (Lepadidae) is from the Pliocene. Some fifty of these fossils were discovered when etching out the chitinous skins of Eurypterus fischeri Eichw. from the Upper Silurian limestones of the Island of Oesel in Esthonia. Some were still attached to the legs of the Eurypterus, clustering on them as do the young Lepas on bits of sponge, cuttle-bone, etc