PLATE 40 G. 



Fig. 1. 570. 2. DiCTYONEMA GRACILIS. ( P^g. 175.) 



1 a. A portion of a frond, showing the brandies neatly defined, and spreading only in a moderate degree. 

 1 /(. A part of another frond, where the branches appear to spread more rapidlj', but have otherwise the 



essentia: characters of tlie preceding. 

 1 c, c. Enlargements, showing the indented or corrugated surface of the branches. 



1 d. An enlargement of several branches, where the margins appear indented or subserrate. 



Fig. 2. 571. 1. Inocaulis plumulosa. ( P^^g- 176.) 



2 a. A part of several stems upon tlie surface of the shale. 

 2 6. An enlarged portion, showing the structure. 



