254 ALG.E. 



seeds, forming distinct sori or groupes (mostly arranged in longi- 

 tudinal lines). Grev. 



Tribe VII. FuRCELLARiEiE. Marine plants, of a dull dark- 

 purplish or brownish-red colour, changing to black on exposure 

 to the air. Substance cartilaginous. Structure cellular, ivith a 

 dense colonized stratum of horizontal filaments, forming ths cir- 

 cumference. Root creeping. Frond cylindrical, filiform, di- 

 chotomous. Fructification terminal, composed of pod-like inde- 

 hiscent receptacles, within which is imbedded, near the circumfe- 

 rence, a horizontal circular stratum of dark-brown oblong-pear- 

 shaped seeds. Grev. 



22. Furcellaria. Frond cartilaginous, cylindrical, filiform, 

 dichotomous. Fructification; terminal, elongated pod-like re- 

 ceptacles, containing a stratum of dark, oblong-pear-shaped 

 seeds in the circumference. Grev. 



Tribe VI 1 1. Spongioc arpe/e. Marine plants, of a dull dark 

 reddish-purple colour, changing to nearly black on exposure to 

 the air, of a cartilaginous substance and cellular structure. 

 Foot scutate. Frond filiform, cylindrical and dichotomous. 

 Fructification uniform, consisting of naked, spongy warts, com- 

 posed of a mass of radiating filaments, among ivhich are imbed- 

 ded numerous, roimdish clusters of seeds, surrounded with a 

 pellucid border ; the seeds wedge-shaped, fixed by their base to a 

 central point. Grev. 



23. Polyides. Frond cartilaginous, filiform, cylindrical. 

 Fructification; naked, spongy warts, composed of radiating 

 filaments, among which are imbedded roundish clusters of wedge- 

 shaped seeds, surrounded with a pellucid border. Grev. 



Tribe IX. Floride^:. Marine plants, of a purplish-reddish or 

 fine rose colour, seldom changing much by exposure to the air ; 

 of a coriaceous, cartilaginous or membranaceous substance and 

 cellular texture, often reticulated. Frond fiat, compressed or 

 cylindrical, with or ivithout a midrib ; sometimes furnished with 

 distinct leaves or foliaceous expansions. Fructification often of 

 two kinds ; the first, spherical or hemispherical capsules, sessile 

 or stalked and containing a round mass of seeds — the second com- 

 posed of granules, (^mostly ternate) scattered or collected into 

 little spots (sort) or lines, and situated either in the general sub- 

 stance of the frond, or in leaflets or distinct pod-like foliace- 

 ous processes. More than one kind of fructification is never 

 found upon the same individucd. Grev. 



24. Delesseria. Frond rose-red, flat, membranaceous, 

 with a percurrent midrib. Fructification of two kinds : — cap- 

 sules containing a globular mass of seeds, and ternate granules, 



