Smithsonian Report, 1915. — Walcott. 



Plate 5, 



o 



1 



8a 



Microscopic Cells from Recent Blue-Green Alg/e and Their Algonkian 

 Representatives. 



Figs. 1 to 6a are from the ancient forms Xrwlandia and Camania; figs. 7 to Sa are from the recent 



Blue-Green Algae. 



