Figs 39–45. Mastogloia belaensis M in Morphology of two Mastogloia species (Bacillariophyta) from Lac de Guiers (Senegal) and comparison with the type material of M. braunii

Figs 39–45. Mastogloia belaensis M.Voigt. Scanning electron micrographs (SEM) of valves from the Lac de Guiers population (Van de Vijver sample SEN-42). 39. SEM internal view of an entire valve with the typical partectal ring. 40–41. SEM internal details of the partectal ring near the valve apices showing the cleft with the lacunae. 42. SEM internal detail of the central area. 43. SEM internal detail of the valve apex with the pseudoseptum. 44. SEM internal detail of the partecta showing the partectal walls with 2–4 series of small, rounded pores. 45. SEM internal view of the inner areolae arranged in groups of 4–8 per pseudoloculus. Scale bars: 39–43 = 10 µm; 44 = 5 µm; 45 = 1 µm.