Ser. Rhodosperme^. I'ain. Helmintkocladece. 



Plate CXXXVI. 

 GALAXAUM (MICROTHOE) MARGINATA, z«.y^^. 



Gen. Char. Frond dichotomous, thinly incrusted with carbonate of lime, 

 constricted as if jointed, or continuous, composed of longitudinal, 

 colourless, interwoven, and anastomosing medullary filaments, and 

 closely placed, inflated or tabular, coiouved perip/ieric cellules. Fruit 

 unknown. — Galaxaura [Lamx.), a classical name; one of the 

 Oceanidse of Hesiod. 



From dichotoma, calcureo-lncrmiata, articnlato-constricta v. contbma, plus minus 

 ti'ansversim rur/ulosa, ex filh medullar ib us tenuibns hyalhiis longitudinalibus 

 interlextis anaslomoscoiiibus, et cellulis periphericis subuniseriatis coloratis 

 injlatis libe?'is v. complanatis, arde co]i(xrentibus, formata. Fructus ignotus. 



Galaxaura (Microthoe) marginata ; stem cylindrical, hirsute, repeatedly 

 forked, its branches bearing flabelliform, fastigiate, dichotomous 

 fronds; segments linear, flat, slightly thickened at the margin, ob- 

 tuse; peripheric cells obovate, inflated. 



G. marginata ; stipite cylindraceo Jiirsuto pluries furcato ; ramis frondes flabelli- 

 formes fastigiatas dichotomas ferentibus ; lacbdis linearibus planis marginatis 

 obtusis ; cellulis perlpUericis obovatis injlatis. 



Galaxaura marginata, Lamx. Pohjp. p. 264. Dene. Cor. Ann. Sci. Nat. 2. v. 

 18.^. 114. KUtz. 8p). dig. p. 530. 



Corallina marginata, Ell. et Sol. p. 115. t. 22,/. 6. 



Hab. Rottnest Island and King George's Sound, Western Australia, abun- 

 dant, r. H. //., G. Cllftoyi. Newcastle, New South Wales, W. H. H. 



Geogr. Distr. Tropical Atlantic and Pacific Oceans. Indian Ocean. Port 

 Natal. Kio Janeiro. Japan. Peejee and Friendly Islands, etc. 



Descr. Root a fleshy disc, covered with hair-like filaments. Plant tufted, dior- 

 ganous, consisting of a cylindrical stijjes and ^ai fronds. Stipes 1-2 inches 

 high, rarely simple, mostly 2-3 times forked or fasciculately branched, cylin- 

 drical, rigid, 1-li line in diameter, densely clothed with horizontal, deep- 

 red, jointed hairs. Frond springing from the apices of the branches of the 

 stipes, 2-5 inches long, about 1^ line wide throughout, flabelliform in ex- 

 pansion, many times dichotomous, the segments erecto-patent, linear, flat, 

 obtuse, slightly thickened or inflexed at the margin, scarcely channelled, 

 with a minutely granulated, microscopically mottled surface. Apices com- 

 monly obtuse or emarginate, sometimes (as in Pig. 2) crowned with bright 

 crimson, duplicate, brush-like tufts of articulated filaments. Tliese brush- 

 like tufts are probably connected with the fructification ; the filaments com- 

 posing them are either uniformly cylindrical, like paranemata, or some of 



