FUCACE.E. 11 



** Frond formed of jointed filaments, which are either free or united 

 into a compound body. 



5. CHORDARIACE.E. Frond cartilaginous or gelatinous, 



composed of vertical and horizontal filaments inter- 

 laced together. Spores immersed. 



6. ECTOCARPACE^E. Frond filiform, jointed. Spores ex- 



ternal. 



ORDER I. FUCACE^. 



J. Ag. Sp. Alg. vol. i. p. 180. C, Ag. Syst. Alg. p. xxxvii. 

 (in part). Decaisne, Ess. p. 34 (in part). Fucoideae, Grev. 

 Alg. Brit. p. 1. Harv. Manual, 1 edit. p. 1. Fuceae, 

 Cystoseireae, Sargasseae and Halochloae, Kutz. Phyc. Gen. 

 p. 349. Fucidae and Cystoseiridae, Lindl. Veg. King. p. 22. 



DIAGNOSIS. Olive-coloured, inarticulate sea-weeds, whose 

 spores are contained in spherical cavities immersed in the 

 substance of the frond. 



NATURAL CHARACTER. Root almost always a conical disk, 

 rarely branching or creeping. Fronds of an olive-brown or 

 olive-green colour, becoming darker in drying ; of a tough, 

 leathery substance and fibrous texture, tearing lengthwise 

 with facility ; dichotomous or pinnate, rarely irregularly 

 branched, but very variable in habit. In the simpler kinds 

 (Splancnidiwri) there is no distinction into parts (as stem, 

 leaves and receptacle), but the fructification is equally dis- 

 persed through all parts of the plant ; in others (Durvillaa, 

 Sarcophycus) there is a stem ending in a phyllo-caulon or 

 leaf-like frond, through which the fructifications are scattered; 

 in others (Himanthalia) there is a simple frond of small 

 size, and a branching receptacle of fructification resembling 

 a frond ; in others (Fucus, Cystoseira, &c.) there is a branch- 

 ing or imperfectly leafy frond, some portions of whose 

 branches finally swell, and are converted into receptacles of 

 fruit ; and finally, in the most perfect kinds (Sargassum, 

 Marginaria, &c.) there is a branching frond, with well- 

 formed, mostly distinct and nerved leaves, and receptacles 

 from their origin set apart as organs of fructification (not 

 formed by swellings of old branches), developed either in 



