PLATE XVIII. 

 Sphenoptbbis Brittsii Lx. 



(Page 53.) 



Fig. 1. Fragment with spread pinnules. U. S. Nat. Mus., 5705. 



2. Upper portion of young pinna on which the pinnules are the smallest found. This form is 

 perhaps identical with that listed from the same beds by Professor Lesquereux as Sphen- 

 opteris Gravenhorsiii Brongn. U. S. Nat. Mus., 6669. 

 2a. Enlarged detail of small pinna of same. x2. 



Sphenopteris pinnatifida Lx. sp. 



(Page 45.) 



Fig. 3. A fragment with large pinnules of this species occupies the central and lowei portions of the 

 rock. Small fragments of Callipteridium memtranaceiim Lx. occur on the left center, while 

 pinnEe of Pecopierls veftita Lx. lie near the lateral borders. U. S. Nat. Mus., 5807. 

 4. Apical portion of pinna of Sphenojiteris pinnatifida with smaller pinnules. U. S. Nat. Mus., 

 5803. 

 4a. Enlarged detail from the same, showing lobation of the pinnules. x2. 



346 



