— 179 — 



This interesting species was found growing upon Acanthophora 

 spicifera (Vahl) nob.^) From the basal cell which to begin with 

 is roundish and thick-walled (Fig. \E), short horizontally creeping 

 filaments grow out; some of these are epiphytic creeping upon the 

 surface of the AcanthopJiora, others penetrate into the tissue of the 

 host-plant (Fig. 1 F, G, H, 7.), but it sometimes happens that young 

 plants occur which are not at all parasitic. From this basal layer 

 several erect filaments gradually arise forming a small tuft. The 

 cells which are usually a little constricted at the cross-walls in the 

 lower part of the filaments contain a parietal, well-developed 

 chromatophore often covering nearly the whole cell-wall with the 

 exception of a few small holes, and a large pyrenoid lying on the 

 one side of the cell (Fig. 1 D). 



The cells in the lower part of the plant are about 2^/2 times 

 as long as broad, in the upper part they often grow shorter, being 

 commonly only P's as long as broad; an exception from this is 

 found however in the young plants which are still growing quickly, 

 where the cells at the top also reach a length of 2^/2 times the 

 breadth. The filaments are most often bare in the lower part but 

 ramified from about their middle ; the side-branches grow at an 

 acute angle from the mother-branch. In well-developed plants the 

 branches ramify richly on all sides and they may also be again 

 branched. 



The monosporangia are by far the most common : the greatest 

 number of specimens possess only these. They are narrow ovate, 

 often almost cylindric, most often sessile, uniseriate upon the upper 

 side of the branch (Fig. 1 B). When a sporangium has been emptied 

 a new sporangium very often grows out in its place. 



Only 2 — 3 plants with sporangia having two spores were seen 

 (Fig. 1 A, C.) ; these sporangia are larger than the monosporangia, 

 oval and divided by horizontal walls; they are also mostly sessile, 

 seldom stalked; also here a new sporangium often grows out when 

 the old is emptied. I may also point out that once a single spo- 

 rangium was found in which the upper half-part was again divided 

 by a vertical wall. 



Hairs do not occur. 



This species seems to be nearly related to Ch. Hypnece^) 



*) Concerning this name see later. 



2) B0rgesen, F., Some new or little known West Indian Florideae (I). Bota- 



nisk Tidsskrift. 30. Bd. 1909, p. ± 



12* 



