F. Børgesen: Rhodophyceæ of the Danish W. Indies, 



393 



A few specimens of this plant have been found. They are 

 fixed to the substratum by means of a small disc, having a 

 cuneate rapidly expanded base which is afterwards divided into 

 several lobes. These lobes bear along their margin several smaller 

 ramifications, in my specimens they are of an elongated oblong 

 shape tapering towards both ends. 



The thallus is flat, compressed, in places nearly compact, 

 but here and there smaller or larger openings are present be- 

 tween the innermost large cells (Fig. 375 a). These cells are 



Fig. 376. Chrysymenia Agardhii Harv. 



A, wall of frond seen from innerside; the cell to the left with glands (70:1); 



B, transverse section of the wall; the cell in the middle with a gland (70:1); 



C, part of a cell with glands (170:1); D, tetrasporangia in the cortical 



layer (170:1). 



oblong to oval of shape when seen from the surface (Fig. 376 A), 

 in transverse section irregularly polygonal (Fig. 376 B). The sur- 

 face consists of a dense layer of small cortical cells covering the 

 underlying large cells completely. 



On their innerside, facing the cavities in the interior of the 

 thallus, one of the large cells bears here and there a few (2 — 4 

 seldom more) scattered gland-cells (Fig. 375 a, 376 A). These 

 are globular to obovate. 



Furthermore hyphæ-like filaments grow out in all directions 

 from the innerside of the large wall cells filling up the cavities 

 more or less (Fig. 375 a). These filaments have transverse walls 

 and are sometimes ramified. The cells in the filaments are nearly 

 cylindrical, about 20 /i thick and five to eight times as long. Such 



