88 



Fig. 139- Surirella oval is , (5), cells 20-100u long, 10-k0\i wide; 

 1.5-5 longitudinal folds in 10m; striae distinct, about 

 16 in 10u. X 1000. 



valve view 



girdle view 



Notes : 



Fig. 1^0. Surirella ovata , (5), cells 10-70u long, 8-23n wide; 



longitudinal folds extend to the center, <^-7 in lOu; 



striae fine but distinct, 16-20 in lOu. X 1000. Common 

 in the southwest. 



valve views 



Notes : 



