Pavlova ennorea sp. nov. is described at both the light and electron microscope level with emphasis on the palmelloid stage. Characteristic features of the genus Pavlova observed in our material include the reserve material paramylon, the system of flagellar roots, and the pit entering the cell at the flagellar pole. The flagellar apparatus and the pit are not continually present in the encapsulated condition. An investment of minute dense particles on the plasmalemma, as known from other Pavlova species, is completely absent. In Pavlova ennorea, ecdysis of the periplast is a natural phenomenon, in which the plasmalemma is replaced by a membrane of the endoplasmic reticulum. The original plasmalemma and the substituting E.R. membrane have dissimilar garnitures of internal particles, which suggest that periplast ecdysis effectuates a change in the protoplast’s boundary conditions. The mucilage envelope is composed of long microfibrils. Staining experiments indicate an anionic nature of the mucilage. However, the permeability for anions seems not impaired to a biologically signifidegree.