(het-err-o-knee-ma), a genus of heterotrophic euglenid flagellates. With two flagella, both of which are thicker than usual flagella. One flagellum projects anteriorly, one trails behind or to the side of the cell. There is an ingestion apparatus, which included two stiff refractile rods that are used to manipulate food into the mouth. They can be seen just posterior to the insertion of the anterior flagellum. Differential interference contrast.