hi 



Fig. 50. Fragilaria intermedia , ( 5 ), cells 15-60u long, 2-5n wide; 

 9-13 striae in lOu; central area clear on one side only. 

 X 1000. 



^nTrfflTTTm 



mmumm i i— umiuumiii 



Juiuiiiu:." ■■ 



cuiniiiun 



rnnimu 



II MJi 



■ 1 1 . 1 1 r i n 

 milium ii.iiui hi Hum ] iu 

 hrrirminTiii 1 1 1 1 itt«^i nA 



(111)111 1 1 It 

 mm" 



valve view 



girdle view 



Notes: 



Fig. 51. Fragilaria leptostauron , (12), cells 13-30|i long, 10-l6u 

 wide; striae coarse, 6-9 in lOu. X 1000. 



' 



•A 



-;*•• 



rac 



*"T3 



«?' 



n 



valve views 



girdle view 



Notes 



Fig. 52. Fragilaria pinnata , ( 5), cells 3-30u long, 2-6u wide; 



striae coarse 10-12 in lOu. X 1000. Widely distributed. 



valve view 



girdle view 



Notes : 



