x LIST OF ILLUSTRATIONS. 



I'AGE. 



MEGASPORE OF ISOETES FOVEOLATA 241 



MEGASPORE OF ISOETES GRAVESII 2 43 



MEGASPORE OF ISOETES MELANOSPORA 2 44 



MEGASPORE OF ISOETES FLACCIDA 2 44 



MEGASPORE OF ISOETES HOWELLI 2 4 6 



MEGASPORE OF ISOETES MELANOPODA 2 5 r 



MEGASPORE OF ISOETES BUTLERI 



MEGASPORE OF ISOETES NUTTALLII 



MEGASPORE OF ISOETES ORCUTTI 



MEGASPORE OF ISOETES MINIMA 2 54 



