MARINE ALGAE FROM EASTER ISLAND 



260 



K. vagans nov. s[>cc. - Fig. 15. 



Thallus divaricatus in superficie corticis hospitis [Cruoriella spec.) vage 

 circumrcpens. e filamentis inegulariter ramosis compositus. 



Ramificatio aut alterna aut secunda, longa parte filamentorum nuda. 



Cellulis aut cylindricis, ca. 4— 5 latis et 30 a vel ultra longis, aut magis 

 irregulariter forraatis, curvatis sinu- 

 osis, raro furcatis. 



Chromatophora parietal ia lo- 

 bata. 



Sporangia fere rotundata, ca. 

 4 [i lata. 



The plant (Fig. 15) described 

 here was found on a sterile crust of 

 a Cruoriella. It creeps divaricately 

 in the thick epidermal walls of the 

 host forming, when systems o\ 

 branches from different plants meet, 

 a more or less dense network above 

 the cells of the host. 



The filaments are irregularly 

 ramified sending out a side branch 

 now and then at both sides (Fig. 

 1 5 c). The branches are sometimes 

 alternate, sometimes more secund; 

 often a branch is borne by every 

 cell in the filament, often, too, long 

 series of cells are destitute of 

 branches. The filaments have apical 

 growth; when the apical cell has 

 reached some length it is divided 

 by a transverse wall into two cells. 



The cells sometimes are quite 

 or almost cylindrical, about 4 — 5 ;j. 

 broad and often more than 30 ;j. 

 long, but oftener very irregular in 

 shape, curved, sinuated, even sub- 

 furcate. In the cells a well developed 

 parietal, lobed chromatophore is 



present, now and then leaving a space free; no pyrenoids were observed with 

 certainty. 



The sporangia (Fig. 15 c, d, e) are cut off from the vegetative cells by 

 means of an oblique curved wall, in accordance with the description of RoSEN- 

 VIXGE. As the figure shows, the formation of the sporangia takes place both 

 in the apical cell and in the intercalary cells; in one case the outgrowth of a 

 sinuated cell had become transformed into a sporangium (Fig. 15 d). The 

 spores are roundish, or somewhat flattened on one side and measure about 4 a 



Fig. 15. Erythrocladia vagans nov. spec, a and b 

 parts of the thallus, c. 520 />; c, d and e parts of fila- 

 ments with sporangia, c. iW> ji. 



