MARINK ALGAE PROM EASTER ISLAND 



2 59 



In the basal part the cells are broader than long and more or less coherent, 

 forming a nearly parenchymatic tissue (Fig. 9 a). While this horizontal layer 

 in Mine. WEBER's plant is composed only of 1 — 4 layers of cells, ten or even 

 more are not uncommon in my plant. The cells are considerably broader than 

 long, ca. 1 S jx broad and only 7 a high. The filaments composed of these cells 

 are now and then dichotomously divided; generally they are vertical, but now 

 and then parts of the tissue occur with curved filaments. 



Above this tissue the filaments become thinner and at the same time 

 mutually free in their whole length. In this respect our plant differs essentially 



Fig. 9. Mesosfiora VanBosseae nov. spec, a transverse section of thallus, c. :co /i; b part of 

 margin seen from above, c. ,30 /i; c assimilating filaments and hairs, c. 150 /i; d formation of 



plurilocular sporangia, c. 20 ° 1. 



from that of Mme. Weber, who describes her plant in the following way: »Les 

 filaments verticaux, claviformes qui la composent ont de 10 — 20 cellules, ils 

 sont libres dans la partie basale et mediane, mais adherent fortement entr'eux 

 au sommet, couvert d'une couche mucilagineuse assez epaisse*. In our plant 

 as explained above the basal parts of the filaments adhere rather firmly while 

 upwards the filaments become quite free, only imbedded in mucilage. 



At the base of the free part of the filaments the cells are cylindrical and 

 as much as 24 a long and 8 — 11 a wide; higher up the cells grow shorter, 

 mostly broader than long, the width of the filaments being about 16 a. 

 The filaments consist of about 20—30 cells. Thus, they are a good deal 

 longer than in Mcsospora Schmidtii: furthermore the shape of the cells is 



