— 200 - 



This Rhodomelacea remarkable for its 3 pericentral cells has 

 earlier, so far as I know, been found in America only at the 

 Bermuda Isles. It was therefore of special interest to me to com- 

 pare my plant from St. Croix with that from the Bermudas. At 

 my request Mr. Frank S. Collins has most kindly sent me a 

 specimen of the Bermuda plant. From this the agreement with 

 my plant was quite clear and my plant also seems to agree very 

 well with the description of Falkenberg, the filaments being only 

 somewhat thinner. While namely, after De Toni, Sylloge Alg., 

 Vol. IV, Sectio III, p. 864—5, these reach a thickness of 60—70 ^ 

 and in the dried Bermuda specimen about 50 p. the filaments of 

 the West Indian specimens were only 30 — ^ fx thick. 



Fig. 17. Fallienhergia Hillebrandii (Born.) Falkenb. 



A, part of a plant (25:1). 5 and C, apices of plants (150:1). /), part of a filament (120:1). 

 E transverse section (150 : 1). F, G, hapterse (65 : 1). 



Epiphytic upon other algse the irregularly ramified and twisted 

 filaments of this species (Fig. 17 A) form densely matted tufts up 

 to a height of two— three cm. To the host-plant it is fixed by 

 means of irregularly shaped, often disc-like hapterse (Fig. 17 F, G) 

 emerging from the lowest, more or less horizontally growing and 

 also irregularly ramified filaments. These as well as the hapterse 

 are thick-walled in contrast to the otherwise rather thin walls of 

 the thallus. 



The growth in length of the filaments takes place with the 

 aid of a rather large conical-cylindric apical cell (Fig. 17 B, C), of 

 which the lowest part is gradually cut off by means of a horizontal 

 wall into flat, disc-like segments. These cells are again by vertical 

 walls divided into the small central cell and the 3 pericentral cells 



