— 268 — 



Struvea elegans was dredged in deep water only, down to 

 about 40 meters. It occurs at several places in the Sound between 

 St. Thomas and St. Jan, further near Thatch Gay at St. Thomas 

 where it was collected by Dr. Th. Mortensen and off America 

 Hill on the north side of St. Jan. 



S. anastomosai! s (Harv.) Piccone. 

 A. Piccone, Alghe in "Crociera del Gorsaro aile Isole Madera e Canarie 

 del Gapitano Enrico d'Albertis", p. 20, Genova 1884 1 ). Cladophora? anastomo- 

 sans Harv. in Trans. R. I. Acad., vol. 22, p. 565; Phycologia Australica, vol. II, 

 pi. 101. 



Struvea delicatula Kütz. , Tab. Phycol. , vol. 16, tab. 2. Murray and 

 Boodle. A structural and systematic account of the genus Struvea. (Annals of 

 Bot., vol. 11, p. 265). 



This nice little plant occurs in small, dense tufts in fissures of 

 rocks. The tufted form is due to its mode of growth. From irreg- 

 ularly ramified rhizome-like filaments creeping on the substratum 

 grow the erect stalks which at their summit bear the more or less 

 regular branched fronds. The ends of the branches in this leaf- 

 like part of the thallus fix themselves, as is well known, by means 

 of clamps not only to other filaments in their own leaf but also 

 to other fronds with which they come in contact and in this way 

 the small tufts are formed. M me Weber van Bosse has described 

 this way of growing in a very detailed manner in "Études sur 

 les Algues de l'Archipel Malaisien" (Ann. du Jard. de Buitenzorg, 

 vol. VIII, p. 86—87). 



At first the young plant consists of a nearly cylindric cell, 

 tapering somewhat at both ends, the stalk of the full grown plant. 

 Below it is fastened to the substratum by means of irregularly 

 ramified and septate rhizoids in which starch is accumulated 

 (fig. 15 d). The stipe has quite even walls and has no annular 

 constriction at its base. It is often ramified (fig. 15 d). 



When the stalk has reached a certain degree of development 

 the cell contents are densely accumulated in the top of the cell 

 and then divided into a number of cells (fig. 15 a). This divi- 

 sion takes place so far I have been able to see quite in the same 

 manner as in the above-mentioned species. In spite of the fact, 

 that I have had a fairly large material I have nevertheless only 

 found very few cells in the first stages of development, most pro- 



*) The variety canariensis of Piccone described here is = Struvea ramosa 

 Dickie, as pointed out by Murray and Boodle. 



