Drawing

Description:

Cosmoeca ventricosa Thomsen in Thomsen and Boonruang, 1984. Cells solitary. Cell body when dried 6.7-7.5 x 2.5-4 microns, flagellum about 20 microns long. Lorica barrel-shaped, 23-31 microns high, composed of3 transverse costae and 9-12 longitudinal costae. The two almost equally sized anterior transverse costae (average widths 22.4 microns and 19.2 microns) are located at the anterior end of the lorica chamber and at the level of the joints between the second and the third longitudinal costal strip (counted from the anterior lorica end). The number of strips in both anterior transverse costae corresponds to the number of longitudinal costae. The third minute transverse costa is formed by 3-4 costal strips and located at the level of the joints between the third and the fourth longitudinal costal strip (counted from the anterior lorica end). A numerical reduction in the number of longitudinal costae occurs below the posterior transverse costa.