SYNOPSIS 



OF THE 



ORDERS AND GENERA. 



Sub-class I. MELANOSPERME/E OR FUCALES. 

 (Olive Seaweeds.) 



Order 1 . Fucace^e. Olive-coloured, inarticulate seatceeds, whose spores are 

 contained in spherical cavities of the frond. 



* Air-vessels stalked. 



I. Sargassum. Branches bearing ribbed leaves. Air-vessels simple. 



II. Halidrys. Frond linear, pinnate, leafless. Air-vessels plurilocular. 



* * Air-vessels immersed in the frond, or none. 



III. Cystoseira. Root scutate. Frond much branched, bushy. Receptacles 

 cellular. 



IT. Pycnophycus. Root branching. Frond cylindrical. Receptacles cellular. 



V. Fucus. Root scutate. Frond dichotomous. Receptacles small, filled with 



mucus, traversed by a net-work of jointed threads. 



VI. Himantiialia. Root scutate. Frond cup-shaped. Receptacles very long, 



strap-shaped, dichotomously branched. 



Order 2. SporochnacE/E. Olive-coloured, inarticulate seaweeds, whose 

 spores are attached to external, jointed filaments, which are cither free, 

 or compacted tor/ether into knob-like masses. 



* Spores attached to pencilled filaments. 



VII. Desmarestia. Frond solid, distichous, filiform, or flat. 



VIII. Artiirocladia. Frond filiform, nodose, traversed by a jointed tube. 



* * Spores in knob-like receptacle*. 



IX. Sporociinus. Receptacles hi cya\, stalked. 



X. Cahpomitra. Receptacles terminal. 



Order 3. Laminariace.e. Olive-coloured, inarticulate seaweeds, whose 

 spores are superficial, either formimj cloud-like patches, or cover i /it/ the 

 whole surface of the frond. 



XI. Alaria. Stipitatc. Stipes ending in a midribbed leaf. 



XII. Laminaria. Stipitatc. St/pes ending in ;i riblesi leaf. 



XIII. Chorda. Frond leafless, cylindrical, bolloi ; the cavity inte rr up ted bj 

 transverse partitions. 



a 



