Drawing

Description:

Anisonema orbiculatum Lackey, 1940. Cells are 12-25 microns long, circular in outline, slightly rounded above but flattened ventrally, except for a wide, rather deep groove in the median plane. There are two flagella, emerging on the left ventral side through a somewhat crescentic sub-terminal mouth opening into a shallow gullet. Below this also on the left side is a relatively conspicuous nucleus. The short anterior flagellum is thin, about body length, the trailer stout, about twice body length and carried straight bade. No stigma or color. Numerous inclusions, mostly small spheres, in the cytoplasm. Pellicle firm, smooth. Movement principally a steady glide forward. No observed ingestion of food. Reproduction not seen.