On the Pithophorace^e. 



77 



11. Piece of a sterile specimen broken off at the lower end. The lowest cell 

 left is forming a rhizoYd-resembling cell, rl, in its lower end. 



12. The same as in the preceding figure, but the rhizoid-like cell, rl, is here 

 fullgrown. 



Figs. 13 to 15. P. Oleveana nob. 



13. A fertile specimen, rather small, but complete. No rhizold exists. In its 

 place the lowest cell of the cauloi'd has formed a new basal spore within the 

 membrane of the old mother spore, sgb. 



14. A piece of the cauloid of a fertile specimen. In the principal filament 

 several inclosed pairs of twin spores s', s" are found. 



15. A piece of the caulo'id in a fertile specimen. In the principal filament a 

 group of triple spores, s 1 , s 2 , s s , are found; in each of the branches a terminal 

 pair of twin spores, s\, s", exists. 



PLATE III. 

 All the figures are magnified 200 times. 



Pithopliora kewensis nob. 



1. Two cells of the principal filament of a sterile specimen. The lower, p, is a 

 prolific cell. In the upper, the formation of a branch has just begun. 



2. A cell from a sterile specimen, which cell is in the act of forming a 

 branch. The branch-process has just attained the size which it is to attain 

 before the formation of the parting wall between the branch cell that is to 

 be and the older part of the mother cell is commenced at the base of the 

 process. The contents of the cell are not represented. 



3. Part of a cell belonging to the rhizoid of a sterile specimen. The granules 

 of chlorophyll are arranged so as to form a net. 



4. A cell, in which the formation of the spore has begun by its upper part 

 having been somewhat enlarged. The contents of the cell, which are not 

 represented, have not yet begun to pas< towards the upper part of the cell. 



5. An inclosed cell which is forming a branch and in its top a spore, st. 

 When the terminal spore that is to be, st, is almost filled with chlorophyll, a 

 parting wall will first be formed at the base, ba, of the branch cell that is to 

 be, and after this, when all the chlorophyll in the lowest part of the branch 

 cell has passed into the spore, a new parting wall will be formed at the base, ba, 

 of the spore that is to be. All this being done, the chlorophyll left in the 

 original mother cell is used for the formation of a spore in the upper part of 

 the mother cell. 



6. A spore-forming cell, where the body of chlorophyll is passing into the 

 spore that is to be, s. 



7. An inclosed cell, cp (of the principal filament), which has formed first a 

 branch cell, b, and in its top a terminal spore, st, and is now in the very act 

 of forming in its own upper end an inclosed spore, s. 



8. A piece of the principal filament with a group of seeming triple spores. A 

 lower mother cell, situated below the oblique parting-wall, w, has formed in its 



