Ser. RnoDOSPERMEiE. Fam. Ilhodymeniacea. 



Plate LIV. 



RHABDONIA COCCINEA, Harv. 



Gen. Char. Frond filiform, decompound, imperfectly tubular ; tube partly 

 filled with longitudinal, branching and anastomosing filaments ; peri- 

 pheric stratum composed of polygonal cellules, smaller toward the cir- 

 cumference. Fructification : 1, conceptacles immersed in the branches, 

 suspended among the axial filaments and enclosed in a network of 

 filaments, containing moniliform strings of spores, radiating from a 

 central placenta; 2, zonate tetraspores dispersed through the super- 

 ficial stratum. — Rhabdonia (Harv.), from pafiSos, a twig; in allusion 

 to the twiggy ramification of the species. 



Frons fiUformis, decomposite ramosa, tubulosa ; tubo fills longitudinallbus ramosls 

 anastomosantlbus percurso ; strata peripherlco ex cetlulls angulatls sitperficlem 

 versus mlnorlbus contexto. Fruct.: 1, cystocarpla infra stratum peripherlcum 

 suspensa, retlculo filorum velata, carpostomlo demnm aperta, fila sporifera 

 monlliformia a placenta centrali emissa continentla : 2, tetraspora zonatim 

 dlvlsee, per ramos mlnores sparsce, immersae. 



Rhabdonia coccinea ; frond bright-red, stipitate, dendroid, very much 

 branched and bushy ; branches several times alternately divided, all 

 the divisions tapering to an acute point and constricted at base ; con- 

 ceptacles immersed in the ramuli. 



R. coccinea ; fronde rubro-cocclnea stipltata dendroldea dense ramosissima ; 

 ramls plurles alterne dlvlsis, ramulls basi constrlctis apice attenuatls a cutis ; 

 cystocarpils ramxdls idtlmis immersls. 



Rhabdonia coccinea, Harv. in Hook. Lond. Journ. Bot. v. §.p. 408. Kiitz. 

 Sp. Alg.p. 723. J. Ag. Sp. Jig. v. 2. p. 534. 



Rhabdonia Harveyi, Sond. in Linn. v. 25. p. 681 {pro parte). 



m 



Chrysymenia coccinea, Harv. Lond. Jour. v. 3. p. 448. 



Hab. Cast ashore from deep water. At Georgetown, Tasmania, Mr. 



Gtmn, W. H. H., etc. ; and at Brighton beach, Port Phillip, IF. H. H. 



Common. 



Geogr. Distr. South coast of New Holland. Tasmania. 



Descr. Roots, a mat of creeping, branched, twisted fibres. Fronds tufted, 

 6-10-12 inches high, as thick or twice or thrice as thick as hog's-bristle, 

 cylindrical, attenuated upwards. The stem generally rises to the height of 

 1-3 inches before it emits branches ; from thence to the summit it is closely 

 set with alternate, or irregularly inserted branches, directed to all sides. 



