EXPLANATION OF PLATE. 



All figures are Camera drawings, with the exception of fig. 12. 



1. Longitudinal section of a frond through a geniculum ; Corallina chilensis. The 

 extragenicular portions of the genicular cells are shown by the fine lines. X(50. 



2. do. Cheilosporum frondescens. xGO. 



3. Longitudinal section of a frond of Amphiroa aberrant. Observe that the genicula 

 of the axial articulus and of pinnae originated from different zones. X40. 



4. Longitudinal section of a frond through geniculum; Cheilosporum anceps. The 

 shaded portions gain a deeper stain from the colouring reagents. X285. 



5. A meridional section of a frond through the young geniculum ; Amphioa dilatata. 

 X40. 



0. do. Amphiroa epherœa. X40. 



7. Longitudinal section of a frond of Amphiroa aspergillum. X40. 



8. do. Amphiroa stetligera. xOO. 



9. Longitudinal section of the circumgenicular cortex of Corallina chilensis. xl65. 



10. do. Cheilosporum frondescens. X105. 



11. A portion of fig. 5. x650. 



12. The meeting points of the genicular cells of above : highly magnified. 

 18. Cross section of the genicular cells of Corallina yenoshimensis. X285. 



14. do. of Amphiroa aber rans. X285. 



15. External portion of a geniculum attacked by parasitic Diatom ; cut lengthwise : 

 Amphiroa aberrans. x285. 



Ki. External portion of a geniculum of Corallina chilensis : cut lengthwise. X285. 

 17. Cross section of a geniculum of Amphiroa aberrans; about the middle portion. 

 X285. 



