EXPLANATION OF PLATE 3. 



Fig. 1. DiCTYONEMA RETIFORME (Hall), p. 23. 



la. Branch enlarged. 

 Fig. 2. Young frond of same species. 



2a. Branch enlarged, 

 Fig. 3. Calyptograptus cyathiformis (Spencer), p. 28. 

 Fig. 4. Calyptograptus micronematodes (Spencer), p. 29. 



4a. Branch enlarged. 



