71 



Fig. 107. Stauroneis crucicula , (l), cells 30-3%* long, Q-12\i wide; 

 striae parallel to the branches of the stauros, 2k in lOu. 

 X 800. 



valve view 



Notes 



Fig. 108. Stauroneis phoenicentron , (ll), cells 70-325n long, l6-53n 

 wide; striae distinctly punctae, 12-20 in 10n. X 1000. 



valve view 



Notes : 



3*rt> Central area not extending to the margins of the valve, striae 

 present along lateral margins of the central area - NAVICULA 



