427 



The above mentioned non-colouring of the wall of Rhizodo- 

 nium with Chlor-Zinc-Iodine is of no use as a means of distinction, 

 as the wall of Chsetomorpha, too, does not show the common 

 reaction of cellulose. 



Finally I agree absolutely with STOCKMAYER when he recom- 

 mends to study these plant upon living material. 



Among the fixed forms I think the two forms mentioned be- 

 low may be distinguished. 



23. Rhizocloniuin Kochiaimm Kiitz. 



Fig. 406 , 6, c, shows a form in which the cells are from 

 nearly as long as broad up to 2 J / 2 times as long; their diameter 

 varies from 13 to 20 ;JL in length. 



The zoosporangia are a little thicker, about 25 p. 



Another form is figured in Fig. 406 d, e, /, g. It is a little 

 thicker than the above described plant, its vegetative cells reach- 

 ing a breadth of about 20 ^, the length of the cells up to 62 p. 

 The zoosporangia are about 35 p. thick. 



St. Jan: Christiansfort. 



24. Rhizocloniuin Kerneri Stockm. 



Some other of the fixed forms I prefer to refer to this species 

 which is characterized by its somewhat longer cells. 



Fig. 407 a, 6, c shows one form whose vegetative cells are 

 about 10 fji thick and 40 ^ long. It is fixed to the rocks by a long 

 rhizoid formed by throughgrowing of three cells. 



The zoosporangia are often a little narrowed in their middle, 

 about 13 n thick. 



Another form with somewhat shorter cells is figured in Fig. 

 407 d, e. The vegetative cells are about 12 // broad and two to 

 four times as long. 



St. Jan: Christiansfort. 



25. Cladophora unciuata Bergs. 



26. corallicola B0rgs. 



27. fuliginosa Ktitz. 



28. utriculosa Kiitz. 



KUTZING, Phycologia generalis, p. 269; Species Alg., p. 393; Tabulae 

 Phycologicae, vol. 3, tab. 94, fig. 1. Hauck, Meeresalgen. p. 454. 



