PLANTS OF IOWA 85 



1026a. G. acuminatum, Ehrb. 



NAVICULACE.E FAMILY. 



NAVICULA. 



1027. N. nobilis, Kutz. 

 1027a. N. peregrina, Kuetz. 

 1027&. N. viridis, Kutz. 



STAURONEIS. 



1028. 8. phcenecenteran, Ehrb. 

 PLEUROSIGMA. 



1029. P. attenuatum. 



COCCONEMACE^J FAMILY. 



AMPHORA. 



1030. A. ovalis, Kuta. 

 Ponds. 



CYMBELLEJE FAMILY. 



CYMBELLA. 



1031. C. ehreribergii. 



HETEROKONTAE. 



TRIBONEMACKaB FAMILY. 



TRIBONEMA. 



1032. T. lorribycinum, (Agardh.) Derb. & Sol. 



Very common in stagnant water, and even slow flowing 

 water and springs. 



1033. T. bombycinum tenue, Hazen. 

 Slough; in pond amid Lemna. 



1034. T. utriculosum, (Kutz.) Hazen. 

 In rain barrels and in ponds. 



BOTRYDIACE-flB FAMILY. 



BOTRYDIUM, Wallr. 



1035. B. granulatum, (L.) Grev. 



Occurs abundantly on mud just drying up, such as that 



