EXPLANATION OF THE PLATES. 

 Plates VIII-XI. — Purple Cuff-Brake. Pellma atropurpurea. Plate 

 VIII. — I. Young plant attached to prothallus. 2-5. Young leaves in early 

 stages of development. Plate IX. — i, 2. Young fertile leaves. Plate X. — 

 Mature highly developed sterile leaf. Plate XI. — i. Mature highly developed 

 fertile leaf. 2. Fertile pinnule, X 2^. 



