Cystoseira.] ALGJE MELANOSPERME.E. 167 



Div. I. MELANOSPERME^E. 



Plants marine; foliaceous, strap-shaped or filamentous; of 

 an olive-brown or olive-green colour. Fructification contained 

 in definite capsules or receptacles, or in distinct sori. 



TRIBE I. FUCOIDE^E. 



Marine plants of an olive-brown colour, changing to black in the 

 air ; of a coriaceous or ligneous substance, densely fibrous, and 

 tearing in a longitudinal direction. Root scutate ; in some species 

 accompanied by creeping fibres. Frond flat, compressed, or filiform, 

 in many producing distinct leaves ; and in most, furnished with vesi- 

 cles or air-vessels. Fructification, spherical clusters of opaque 

 seeds, surrounded bij a pellucid limbus, imbedded in distinct gela- 

 tinous receptacles, and finally escaping by external pores. 



1. CYSTOSEIRA. Ag. Cystoseira. 



Frond compressed or filiform, more or less foliaceous, but 

 without distinct leaves. Vesicles simple, usually in series, 

 innate in the substance of the branches. Receptacles small, 

 cylindrical or lanceolate, terminal. Seeds in distinct cells. 

 Name, wan*, a bladder, and aetpa, a chain ; from the monili- 

 form arrangement of the vesicles. 



1. C. ericoides, Ag. Heath-like Cystoseira. Frond cylin- 

 drical, branched, closely beset every where with very short, 

 subulate, spinous branchlets ; vesicles elliptical, solitary ; re- 

 ceptacles swelling at the base of the terminal spines. Grev. 

 Hook. Br. Fl v. ii. p. 265. E. Bot. t. 1968. 



Rocks in the South and West of Ireland. Bantry Bay ; Miss 

 Hutchins. Miltown Malbay ; W. H. Harvey. 



2. C. granulata, Ag. Granulated Cystoseira. Frond cylin- 

 drical; stem bearing elliptical knobs, each producing a filiform, 

 repeatedly dichotomo-pinnate branch, furnished with remote 

 subulate spines ; air-vessels elliptical-lanceolate, two or three 

 connected together; receptacles elongated. Grev. Hook. Br. 

 Fl. v. ii. p. 265. E. Bot. t. 2169. 



Rocks, and rocky places left by the tide, in the west and south of 

 Ireland. Bantry Bay ; Miss Hutchins. Coast of Clare ; J. T. 

 Mackay. Black rocks, Portrush ; Mr. D. Moore. 



3. C. fceniculacea, Ag. Fennel-leaved Cystoseira. Frond 

 compressed ; stem destitute of tuberous knobs ; branches more 

 or less rough with little hard points, repeatedly pinnate, fili- 

 form ; air vessels solitary, or about two together ; receptacles 



