I III. AXGAE 01 BERM1 DA. 93 



three or four cm. from the base, descending, terete, branching fila- 

 ments, of an average diam. of one half nun., forming a Loose felt. A 

 cro— section shows a densely cellular structure, the cells much smaller 



than in the median layer of the frond, the superficial cells much like 

 those of the frond. From the superficial cells issue, not continuously 

 hut in groups, monosiphonous filament-. 20-25 // diam.. the cell- 2-4 

 diam. Long, nodes somewhat constricted; these filaments are mostly 

 simple, occasionally with short branches; when a filament reaches the 

 substratum the terminal cell forms a coralloid expansion a- an organ 

 of attachment. Other species of Didyota, I), ciliata for instance, are 

 attached by rhizoidal filaments of a similar character, hut arising 

 directly from the frond; D. dentata is the only Bermuda species in 

 which they arise from descending cellular 1 tranches. In older plant- 

 prolifications are common from the surface of the frond, sometimes 

 papillose to clavate, sometimes flattened with rounded outline. 

 None were observed over 1 mm. in length; the papillose-clavate 

 form seemed to be of a similar character to the descending filaments 

 developed near the base. Antheridia were common in material col- 

 lected in Jan., July and Aug.; no other fruit was observed. 



Dilophus J. G. Agardh. 



D. guixeexsis (Ktitz.) J. G. Agardh, 1SS0, p. 10S; Vickers, 1905, 

 p. 59; 190S, part 2. p. 37, PI. IX; Borgesen, 1914, p. 214, figs. 164 

 165; P. B.-A., Xo. 20S0; Spatoglossum guineense Kutzing, 1843, p. 339; 

 1859, PI. XLVI, fig. I. South Shore near Paget. Farlow; Gravelly 

 Bay, March, Hervey. 



