Except for the mucli greater diameter of the cells composing 

 the filaments of the frond, this species does not materially differ 

 from C. corallina, which is found also on the Australian coast, 

 and which in Tasmania attains a great size. Some allowance 

 may be made for circumstances of growth, and if the size of 

 the whole plant had borne a comparison to the size of each com- 

 ponent " articulation " or cell, I should probably have regarded 

 this present Alga as merely a robust form of G. corallina ; but 

 here we have a peculiarly small or short-growing plant, with 

 constantly much larger cells than are found, except very inciden- 

 tally, in the most luxuriant states of G. corallina. Besides this, 

 the cell-wall in the present plant is much thinner and less gela- 

 tinous than in G. corallina and most others of the genus. 



Fig. ] . Griffithsia ovalis, — the natural size. 2. Apex of a fertile branch, 

 witli two involucres, in situ. 3. Eamelli and tetraspores from an involucre : 

 — magnijied. 



