Plate 13 



Fig. 1. Stigeocloniiim attenuatum (Hazen) Collins, x 750 



Figs. 2, 3. Chaetophora pisiformis (Roth) C. A. Agardh: 2, habit, 

 X 2; 3, portion of thallus, x 500 



Figs. 4, 5. Chaetophora attenuata Hazen: 4, x 440; 5, tip of branch, 

 x750 



Figs. 6, 7. Chaetonema irregulare Nowakowski: 6, filament with 

 oogonium, x 500; 7, sporangia, x 500 



[686] 



