- 243 — 



In the wall-plasma we find the plate-formed chromatophores; 

 they are irregularly polygonal with more or less elongated corners 

 and forming in this way a net-work (fig. 1 e). A rather large pyrenoid 

 is found in each chromatophore, as pointed out both by Murray 

 and Kuckuck. Below the chromatophores we find the numerous, 

 rather regularly distributed nuclei. 



All the specimens I have collected and examined were in a 

 vegetative state as above mentioned ; the fructification most pro- 

 bably takes place at another season than when I have collected 

 in the West Indies (Dec— April). But among the rhizoids of a 

 few specimens I have found some quite young plants with only 

 one or a few rhizoids (fig. 1 a) and these I think originate from 

 germinated zoospores. 



In some few specimens I found the cell-contents accumulated 

 in a number of ball-shaped bodies of larger and smaller size, an 

 appearance also common in many related forms. Murray men- 

 tions them also (1. c. p. 50 — 51). He considers them as "the nor- 

 mal reproductive organs of Valonia". In this I cannot fully agree 

 with him; these bodies being possibly a kind of aplanospores 

 which the plant develops most probably under not quite normal 

 conditions. 



This species is very common in the seas round the Danish 

 West Indian Islands; it occurs both in more sheltered and also on 

 exposed coasts and in shallow as well as deep water down to a 

 depth of more than 30 meters. It is most often attached to stones 

 and shells etc., but may also be found growing upon other algæ. 



Yalonia macrophysa Kutz. 



Kützing, Phycologia generalis, p. 307, Species Algarum, p. 507, Tabulæ 

 phycol., vol. 6, tab. 87, fig. 3. J. Agar dh , Till Algernes Systematik, VIII, p. 97. 

 Kuckuck, Über den Bau und die Fortpflanzung von Halicystis Aresch. und 

 Valonia Ginn, in Bot. Zeit., 1907. 



The specimens found agree very well with the description and 

 figures of Kuckuck, I.e. At the base of the large vegetative 

 cells small lens-shaped cells occur, provided more or less abun- 

 dantly with rhizoids. Also large lens-shaped cells were present in 

 rather great number. 



I w T ould not have kept this form separate from the following 

 species, if Kuckuck had not found differences in their zoospores. 

 This I have not been able to substantiate in my material preserved 



16* 



