portrait

Description:

Cells broadly oval to egg-shaped, with a relatively straight left side and a convex right side, dorso-ventrally flattened. Length 24 - 38 microns, width 17 - 24 microns, length to width ratio 1.3 - 1.6. Epicone 5 - 10 microns at its widest, deflected to the left. Cingulum becoming relatively deep and wide (approximately 2 microns), distal end approximately 4 microns lower than proximal. Transverse flagellum originating in a pocket just below the proximal end of the cingulum. Narrow ventral ridge beginning just to the right of the origin of the cingulum, contininuing down the cell in a straight path, past the distal end of the cingulum to the origin of the sulcus. Sulcus beginning 0.6 - 0.7 of the cell length from the apex, to the left of the mid-ventral line, initially narrow, the left side broadening posteriorly, the right side continuing in a straight line to the posterior end. Longitudinal flagellum arising in a pocket just before the anterior end of the sulcus, approximately 60 microns. Two pusules present, a large (approximately 2 microns diameter) obvious one to the right of the anterior end of the sulcus, and a smaller, less distinct one just below the origin of the cingulum. Apical groove not present. Nucleus in the posterior part of the hypocone, round, 10 -14 microns diameter. Chloroplasts not present. Cytoplasm filled with large colourless lipid globules and occasionally food particles. Non-motile cells round, approximately 45 microns diameter, surrounded by a hyaline layer, showing no detail of cingulum or sulcus.