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Meloslra dlstans alplgena 

 Meloslra granulate 

 M, granulata angustlsstma 

 Melosira lalandlca 

 Meloslra Itallca 

 Meloslra varlans 

 Merldlon clrculare 

 Navlcula canalls 

 Navlcula cryptocephala 

 Navlcula cuapldata 

 Navlcula lncomposlta 

 Navlcula not t i,i 

 Navlcula trlpunctata 

 Navlcula virldula 

 Nltzschla aclcularls 

 Nltzschla aplculata 

 NLtzschla denclcuLa 

 Nlczschla dissipate 

 Nlczschla fonClcola 

 Nltzschla holaatlca 

 Nltzschla hungarlca 

 Nltzschla linearis 

 Nltzschla slgma 

 Nlczschla slgmoldea 

 Nlczschla trybllonella 

 Plnnularla borealls 

 Pleurosigma dellcaCulum 

 Rholcosphenla curvaCa 

 Rhtzosoienla erlensls 

 Rhopalodla glbba 

 S. astraca mlnutula 

 Stephanodlscus dublus 

 Stephanodlscus hantzschla 

 Scephanodlscus nlagarae 

 S. nlagarae var. magnlflca 

 Stephanodlscus tenuis 

 Surlrella angustata 

 Surlrella brlghtwellll 

 'Jurlrella ovata 

 irurlrella etrlatula 

 Synedra acus 

 Synedra pulchelLa 

 Synedra nana 

 Synedra tabulata 

 Synedra ulna 

 Synedra vaucherlae 

 labellarla fenescraca 

 Tabellarla t locculosa 







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a U. S. GOVERNMENT PRINTING OFFICE : 1966 O - 220-505 



