- 135 — 



fied. As to the anatomical characters var. platyloba agrees very 

 well with var. typica, only the peripheral utricles seen from above 

 seem to be a little larger in this form than in var. typica. Com- 

 pared with var. platydisca of H. Tuna in external habit the two 

 forms show great agreement, nevertheless some lesser differences 

 are present; of these may be mentioned that the thallus is thinner, 



Fig. 3. Halimeda discoidea Deeaisne var. platyloba nov. var. 



A young plant with new joints above. About 1 : 1. 



more greenish and less calcified in var. platyloba than in var. platy- 

 disca, just as the surface of the joints seems to be a little smoother 

 in var. platyloba, more uneven in var. platydisca. But in the anatomi- 

 cal characters, as stated before, the two forms are easely separa- 

 ted, each having the characters of the respective typical forms. 



Quite in the same way as var. platydisca, var. platyloba is a 

 deep-water form occurring at the Danish Isles in depths from 



