56 



SEAWEEDS 



CUTLERIACE.E 



General Characters. The reproductive organs of 

 the Cutleriacece are not borne in conceptacles as in the 



Fucaeece, but occur in clus- 

 ters or sori among para- 

 physes on the outer surface 

 of the plant. The oos- 

 pheres are ciliated like the 

 antherozoids, which they 

 greatly surpass in size. 

 Fertilisation is not effect- 

 ed until the oosphere has 

 come to rest. There is 

 also reproduction by non- 

 sexual zoospores, interme- 

 diate in size between oos- 

 pheres and antherozoids, 

 and produced in unilocular 

 zoosporangia, also super- 

 ficial in situation. The 

 growth of the thallus is 

 trichothallic, and in Zan~ 

 ardinia the old fronds 

 give rise vegetatively to 

 new individuals by tricho- 

 thallic gemma3. The order 



is a small one, consisting of the genera Cutleria 

 (including Aglaozonia) and Zanardinia. 



The Thalhcs in both genera (exclusive of the non- 

 sexual generation of Cutleria = Aglaozonia} is of 



FIG. 8. Cutleria multifda. a, 

 female sorus ; b, male ditto 

 highly magnified. 



