Ser. Rhodosperme^. Fam. Uhodymeniaeecs. 



Plate CXLVI. 



RHODYMENIA AUSTRALIS, So,>d. 



Gen. Char, i^rowr/ flat, membranous, dicliotomous or palmate, composed 

 of two strata of cells ; the meduUari/ stratum of oblong, polygonal, 

 larger cells; the cortical of minute, vertically seriated cellules. 

 Fnictlfication : 1, sessile, hemispherical, thick-walled conccptacles, at 

 length opening by a terminal pore, containing densely-packed, spori- 

 ferous filaments issuing from a basal placenta, and surrounded by a 

 gelatinous pellicle ; 3, cruciate or tripartite tetraspores, either scattered 

 over the frond, collected in son, or immersed in terminal, shield-like 

 nemathecia. — Ehodymenia (Grev.), from f)oSeo<i, red, and vfiw, a 

 membrane. 



Trons 'plana, membrauacea, dicltotoma v. palmata, stratis duobns composita ; 

 strata medullari ex cellulis majitscidis oblongis polr/hedris, corticali celliiUs 

 minimis coloratis pluriserialibus conjiato. Fruct. : 1, cystocarpia sessilia, 

 Jiendspharica, intra 'pericarpium C7'assum demum carpostomio apertum Jila 

 sporifera densissime aggregata, e placenta basali emissa, pelUcidd gelatinoso- 

 cellulosd velata foventia ; 3, tetrasporce cruciatim v. triangule divisce, nunc 

 sparstB, nunc in soros subdefinitos collectce v. in nematheciis terminalibus im- 

 mersa. 



Ehodymenia amtralis ; frond stipitate, narrow-linear, many times dicho- 

 tomous, fastigiate, submarginate, or canaliculate ; segments suberect, 

 with narrow axils ; apices abrupt or emarginate ; conceptacles crowded 

 round the ends of the branches ; tetraspores cruciate, vertically lodged 

 in subterminal nemathecia. 



E. austraHs; //•o«(ie stipitata angusto-lineari phiries dichotoma fastigiata submar- 

 ginata v. canaliculaia ; laciniis suberectis axillis angustis apicibiis subtruncatis 

 V. emarginatis ; cystocarpiis circa apices laciniariim congregatis valde convexis; 

 tetrasporis cruciatis in nematheciis subterminalibus iimnersis. 



Ehodymenia austraHs, Sond. Bot. Zeit. 1845, j». 55. PI. Preiss. v. 2. p. 191. 

 Harv. in Trans. R. I. Acad. v. %2. p. 554 ; Alg. Exsic. Aiistr. n. 380. 



AcEOPELTis australis, /. Ag. Sp. Alg. v. 3. p. 609. 

 SPHiEKOCOCCUs australis, Kiitz. Sp. Alg. p. 784. 

 Hab. Western Australia, Preiss. Abundant at Rottnest Island, near Fre- 



mantle, IF. H. H. G. Clifton. 

 Geogr. Distr. Western Australia. 



Descr. Root discoid. Stem 1-3 inches long, firmly cartilaginous or horny, iliue 

 in diameter, forking or breaking up into several branches, each of which 

 terminates in a dichotoraous frond. Fronds (secondary) subflahelliform. 



