84 



or slightly tapering, or a little enlarged towards the tip, with the 

 ends rounded or more frequently obtuse or nearly obtuse, 1.2— 

 1.8 mm. in diameter. Now and then the branches anastomose 

 below, but more often they are free in the central portions and 

 somewhat anastomosed in the peripherical portion of the frond, or 

 not anastomosing at all. Pl. 15, fig. 1 — 4. The surface of the 

 frond is partly rather smooth partly and most frequently provided 

 with local, scaly thickenings especially in the upper part of the 

 branches. 



The form parvicocca is nearly connected with the typical form. 

 It differs by its more anastomosing branches, the central portions 

 often forming smaller lobes or coarse and somewhat lobe-like 

 branches, from which issue small bundles of brachlets, or the upper 

 branches bearing more or less numerous smaller and wart-like 

 processes. Pl. 15, fig. 5 — 8. 



Another form probably belonging to the same species is f. 

 connata. It often fastens itself to or encompasses small stones. 

 It is less branched and the branches are shorter than in the typi- 

 cal form, much anastomosing especially in the lower part, or it 

 forms a rather solid central portion or smaller lobes. The branches 

 frequently are slightly enlarged towards the tip, fastigiate and often 

 furnished with some wart-like process. The ends are as a rule 

 obtuse. Pl. 15, fig. 9—13. 



The form patula on the one side is closely connected with 

 the typical form in habit, and the limits often nearly impossible to 

 draw, but on the other side showing transition to f. connata, also 

 being difficult to distinguish from this form. It forms small spheri- 

 cal or nearly spherical masses about 2 cm. in diameter. The solid 

 central portion is insignificant and the branches more or less 

 spreading, but in general rather straight, fastigiate or nearly fasti- 

 giate, slightly thickened towards the tip, seldom a little tapering, 

 and most frequently with obtuse ends. Pl. 15, fig. 14 — 19. Ho- 

 wever, the branches often are more crowded, forming transition 

 to f. typica, anastomosing below or even nearly towards the apex, 

 or encompassing small stones, furnished with some wart-like pro- 

 cess, and such specimens forming transitions to f. connata. The 



