EXPLANATION OF THE PLATES. 



Plates XXI, XXII. — Slender Cliff-Brake. Cryptogramma Stelleri. 

 Plate XXI. — 1-8. Leaves in different stages of development. Plate XXII. — 

 I. Mature fertile leaf . 2. Mature sterile leaf. 3. Section of fertile leaf, X 2J. 



