64 Adenocystis, Alaria and Saccorhiza. 



EXPLANATION OF PLATE XVI. 



Fig. i. Adenocystis Lesson ii. Nat. size. 



Fig. 2. Cryptostoma ( x 375). 



Fig. 3. Alaria esculenta. Young state, bearing so-called cryptostomata. Nat. size. 



Fig. 4. Surface view of so-called cryptostomata ( x 150). 



Fig. 5. Transverse section of frond, showing very early stage 



of same ( x 375). 



Fig. 6. ,, Advanced stage of same ( x 375). 



Fig. 7. Saccorhiza bulbosa. Mature cryptostoma ( x 375). 



