Ser. Rhodospeume^. Fam. Spharococcoidea ? 



Plate CLXXXVII. 



THYSANOCLADIA OPPOSITIFOLIA, j. Ag. 



Gen. Char. Frond flat or compressed, distichously decomposito-pinnate, 

 formed of three strata of cells ; the medullary of densely interwoven, 

 slender, longitudinal filaments ; the intermediate of roundish-oblong 

 cells ; the cortical of minute, vertically arranged cellules. Fructifica- 

 tion : \, half-immersed conceptacles, containing, within a thick peri- 

 carp, minute spores arranged in spore-threads radiating from a large 

 placenta ; 2, tetraspores ? — Thysanocladia {Endl.), from Ovaava, 

 a fringe, and KKaho<;, a Iranch. 



Frons plana v. compressa, dlsticJie decomposito-pinnata, triplici strata contexta ; 

 medullar I fills longltudinalibus tenuihus articulatis densissime intertextis, inter- 

 medio celluUs majuscidis rotundato-oblongis, corticali celhdis minimis verti- 

 caliter seriatis coloratis composito. Fruct. : 1, cystocarpia semi-immersa, 

 intra pericarpium crassum sporas minutas in fills a placenta tnagna radian- 

 tibus ordinatas foventla ; tetrasporae. ? 



Thysanocladia oppositifolia ; stem and virgate branches compressed, two- 

 edged j the branches denuded at base, closely decompound-pinnate 

 above; pinnse distichous or fascicled, narrow-linear, once or twice 

 pinnulated ; pinnules opposite, subulate, simple or ramuliferous, 

 acute. 



T. oppositifolia ; caule ramlsque vlrgatls compresso-ancipltlbiis ; ramis baslsfsplus 

 denudatls supra creberrime decomposito-plnnatis ; plnnls dlstlckls v.fasclculatis 

 angiiste llnearlbus plnnatls v. blplnnatls ; plnnuUs oppositis subulatls slmpli- 

 clbus V. aplce, ramullferis . 



Thysanocladia oppositifolia, /. Jg. Sp. Alg. v. 2. p. 617. 



Thysanocladia pectinata, Grev. et Harv. Ner. Austr. p. 91. 



Gelidium oppositifolium, Grev. Sand. InLehm. PI. Preiss. v. I.p. 174. Kiitz. 

 Sp. Alg. /?. 766. 



Sph.erococcUs oppositifolius, Ag. Sp. Alg. t. 294 ; Sgst. p. 230. 



IIab. New Holland, Agardh. Swan River, Mylne., Preiss. Rottnest 



Island, W. II. II. Garden Island, in fruit, G. Clifton. 

 Geogr. Distr. West coast of Australia. 



Descr. Root a large disc, nearly an inch in diameter. Stem usually dividing 

 near the base into several, long, simple, virgate, strongly compressed 

 branches or secondary stems, each of which is 6-12 or 18 inches long. 

 These branches, except the young ones, arc denuded for half their length 

 or more, and closely feathered with slender decompound pinna) in their 

 upper half; the older ones frequently however throw out a new crop of 



