38 



to my paper quoted and shall only point out here that I consider 

 Dictyosphxria favulosa as very nearly related to Valonia; the form 

 of Valonia utricularis (Roth) Ag. I have figured (Fig. 18) shows 

 a striking likeness, also having along the edges of the cells a row 

 of small lentiform cells from which rhizoids grow out and fix 

 themselves to the neighbouring cells. I therefore quite agree 

 with MuRKAY, who considers our plant as »one of the simplest 

 forms of valonioid organism«, when he gives the following descrip- 

 tion of it: »In DictyospJiaeria javulosa we have simply an aggre- 

 gate of similar cells not forming a definite frond, but cohering in 



Fig. 22. Dictyosph(xria favulosa (Ag.) Decsne. 

 Habit of plant. (About 1:]). 



an unbranched mass, this colony of units being held together 

 solely by tenacula«. 



Dictyosphxria javulosa occurs in shallow water and often 

 on rather exposed coasts, growing on coral reefs where it is con- 

 stantly under the influence of the waves. Here the specimens 

 are not so very large, seldom more than 4 — 5 cms in diameter 

 and are most often sack-shaped (Fig. 22). But, furthermore, it 

 is found abundantly in deep water down to a depth of about 

 40 meters. Here in the quieter surroundings and in the moderate 



zoospore-t'orination in my abuiidanl material of Dictyosphseria favu- 

 losa but in Dictyosphseria van Bosseae it was found several times and 

 this form is very nearly related to Dictyosphseria Versluysii. 



Having had well fixed material at his disposal Arnoldi has been 

 able to give more detailed descriptions of the cell-wall and cell-con- 

 tents and he has also succeeded in observing the zoospores, which are 

 pyriform and about ^ — 10 // long. 



