PLATE X. 



Mariopteeis sphenopteroides (Lx.) Zeill. 

 (Page 31.) 



Fir;. 1. Portions of fiuadrisectioiis of primary pinnje, showing characteristic apices. U. S. Nat. Mus. 

 5708. 

 la. Enlarged detail of pinna of same specimeu. x2. 



2. Terminal portions of primary pinniB. The convex lamina between the nerves is partially 

 abraded so as to reveal the more deeply impressed nervation in the photograph. U. S., 

 Nat. Jlus., 5707. 



