EXPLANATION OF PLATE 2. 



Fig. 1. DiCTYONEMA EXPANSUM (Spencer), P- ^5. 



Fig. 2. DiCTYONEMA GRACiLE (Hall), p. 24. Only a small portion of 



the frond is represented. 

 2a. Branch of same enlarged, p. 24. 

 Fig. 3. DiCTYONEMA GRACILE (Hall), p. 24. A celliiliferous portion 



of frond found at Hamilton, Ont. 



