95 



little lacerated margin, rather thin and membranaceous, but of 

 a rather firm texture, reminding one somewhat of Udotea, the 

 surface being rather dense and glabrous with distinct zonation. 

 In the interior of the flabellum the filaments are cylindric 

 or sometimes a little subtorulose, seldom even moniliform (Fig. 

 78 a — d) ; above the dichotomy, which is not always so very 

 typical, as one of the branches is most often somewhat thinner 

 and placed to the 

 side, just as some- 

 times filaments di- 

 vided into three 

 branches (Fig. 78 e) 

 occur, the fila- 

 ments are less or 

 not at all con- 

 stricted ; the thick- 

 ness of these main 

 filaments varies 

 from 60 — 70 /^ or 

 a little more. At 

 the surface the 

 filaments divide 

 several times and 

 grow here, rather 

 suddenly, quite 

 thin, the apical 

 filaments reaching 

 6 — 8 /J. in diameter 

 (Fig. 78 f,g). These 

 thin, irregularly 

 branched and rhi- 

 zoid-like ends of 

 the filaments are 



rather firmly 

 woven together 

 and transformed to rather a dense and firm plectenchyma (Fig. 

 78 h). The stipe has a very similar anatomy. The plant is 

 uncalcified. 



The chromatophores are roundish or oblong (Fig. 78 i), 

 lying quite near the thin wall of the cell ; they contain a pyre- 

 noid and are often filled with amylum. 



As I have pointed out in my paper, Howe (1. c.) was the 



Fig. 77. Cladoceihalus lukofuscus (Crouan) Borgs. 

 Habit of plant. (About 1:1). 



