F. Børgesen: List of species. 433 



between the two chromatophores is often rather considerable 

 these being connected by a broader or slender strand of proto- 

 plasm. In the shorter cells the chromatophores gradually ap- 

 proach forming apparently in the young and newly divided cells 

 but a single stellate chromatophore. 



As pointed out by Sauvageau, too, the comparatively small 

 nucleus is found in the strand of protoplasm between the two 

 chromatophores (comp. Fig. 409 a, b.) 



In one of the filaments nearly ripe sporangia were present! 

 The sporangia have thick walls (Fig. 409 c); they are somewhat 

 broader than the vegetative cells, about 50 fi broad, but often 

 not half as long, about 20 //.. In the upper end a few of the cells 

 were divided into two sporangia each. In the fertile filament 

 found, 35 sporangia were present in the row (Fig. 408 g). 



None of the sporangia present were ripe or emptied, but the 

 disposition of the very large zoospores, characteristic of this plant, 

 was clearly seen. 



According to the above description the West Indian plant 

 seems in all essentials to agree with the one from Morocco and 

 the South of France, described by Bornet and Sauvageau. 



It was found with sporangia in the month of March. 



It was once gathered on rocks near the surface of the sea 

 between other small algæ, e. g. CJiætomorpha, Enteromorpha and 

 Myxophyceæ in a rather exposed place where the waves constantly 

 dash the rocks. Another time it was found in a more protected, 

 lagoon-like locality intermingled with a tuft of Hypnea cervi- 

 cornis. 



St. Thomas: near Charlotte Amalia in the Harbour. St. Jan:, Cruz 

 Bay. 



Geogr. Distrib.: Morocco, south of France and Spain. 



2. Ectocarpus Duchassaingianus Grun. 



3. — Mitchellæ Harv. 



4. — couiferus Børgs. 



5. — Rallsiæ Vickers. 



6. — rhodochortonoides Børgs. 



In the diagnosis p. 170 the diameter of the filaments is, on 

 account of a misprint, stated to be 21 //; it is 11 p as is found 

 in the text, p. 171, but this length of the diameter is found only 



Dansk Botanisk Arkiv, Bd. 3. Nr. 1 (1920). 28 



