F. Borgesen: Rhodophyceæ of the Danish W. Indies. 



257 



Fig. 249. Chondria litto- 



ralis Harv. Transverse 



section of a filament. 



(About 50:1). 



The ramuli are clavate-lanceolate of 



shape; they increase gradually from the 



very narrow base until somewhat above 



their middle, from where they taper slowly 



towards the acute summit. This is mostly 



densely covered with trichoblasts. 



The thallus is terete. The central cylin- 

 der is clearly seen upon a transverse section 



(Fig. 249), and is surrounded by roundish cells. 



The peripheric cells are rather small, subqua- 



dratic. The growing point protrudes conically 



and is densely surrounded by trichoblasts. 



The tetrasporangia are formed mostly in the summit of the 



ramuli, sometimes through almost their whole length (Fig. 250); 



often, too, in the upper end of the branch which bears the ramuh. 

 The antheridial stands (Fig. 248 a) are likewise formed in the 



upper ends of the ramuh. The diameter of the antheridial stands 



is about 450 fi long. 



The large cystocarps are placed upon the sides of the ramuli 



(Fig. 248 b) ; sometimes, too, they may occur upon the branch 



which bears the 

 ramuh. The cysto- 

 carps have a short 

 stalk; they are urn- 

 shaped, having a 

 broad, ovate base, 

 and after narrowing 

 upwards, a broad 

 opening. They are 

 about 1,5 mm long 

 and 800// broad. 



The colour of 

 the plant is a brow- 

 nish yellow with a 

 reddish tinge. 



Compared with 

 the description of 

 Harvey, 1. c. my 



plant shows some 

 Fig. 250. Chondria littoralis Harv. a, part of a tetra- rninnr Hifforannoo 

 sporic plant, b, a ramuius with tetrasporangia more "^"^^' uineieaceb. 

 magnified, (a, about 6:1, b, about 15:1). Thus the cysto- 



Dansk Botanisk Arkiv, Bd. 3. Nr. 1 (1918). 17 



