Bd.3 • DANSK BOTANISK ARKIV • Nr. l 



UDGIVET AF DANSK BOTANISK FORENING 



The marine Algæ of the Danish West Indies. 

 Part 3. RHODOPHYGEÆ. 



By 



F. Borgesen. 



INTRODUCTION 



A. 



lS was the case with the parts of "The marine Algæ of the 

 Danish West Indies" pubhshed earher, this third part, containing 

 the Rhodophyceæ, is based especially upon materials collected during 

 my three stays at the islands. 



With regard to West Indian Red Algæ I have already published 

 some papers on the subject, namely: 



Some new or little known West Indian Florideæ, I. (Botanisk Tids- 

 skrift, 30. Bind, København 1909). 



Some new or little known West Indian Florideæ, II. (Botanisk Tids- 

 skrift, 30. Bind, København 1910). 



For the sake of completeness I have included here the principal 

 contents of these papers. 



The Red Algæ are common in the litoral region and also in 

 the upper sublitoral, but they occur especially in deep water, 

 and where I succeeded in dredging in such places I always had 

 good results. 



Thus they occurred abundantly in the Sound between 

 St, Thomas and St. Jan, Strong currents run here in the 

 narrow channel and steadily renew the water. The depth varies 

 from 10 to about 20 fathoms, seldom more. The bottom is suitable 

 for dredging ; it consists of smaller and larger stones, pieces of 

 corals etc. Upon these a very rich vegetation of algæ is present, 

 mostly consisting of Red Algæ. Also north of St, Jan, in the 

 narrow sound between this Island and Tortola, a flourishing algal 

 vegetation is found, including especially many Red Algæ. 



Dansk Botanisk Arkiv, Bd. 3. Nr. 1 (1915). 1 



