Ser. Rhodosperme^e. Fam. Uh.odymenia.cea. 



Plate XIII. 



ARESCHOUGIA AUSTRALIS, Harv. 



Gen. Char. Frond linear, compressed, distichously branched, midribbed ; 

 composed of an articulated axial filament and three strata of cells ; 

 the medullar// stratum consisting of longitudinal, anastomosing, in- 

 terwoven filaments j the intermediate of several rows of roundish, 

 coloured cells; the cortical of very minute, vertically seriated cellules. 

 Conceptacles immersed in the frond, suspended among the filaments 

 of the medullary stratum, and enclosed in a network of filaments, 

 opening by an external pore, and containing moniliform strings of 

 spores, radiating from a central placenta ; spores roundish, seriated. 

 — Aresohougia (Harv.), in honour of Dr. J. E. Areschoug, Professor 

 of Botany at Upsal, a distinguished algologist. 



From linearis, compressa, distiche ramosissima, immerse costata, e Jilo centrali 

 articidato et stratis tribus cellularum constituta. Stratum medullare e jilis 

 articulatis longitudinalibus anastomosantibus intertextis, intennedium e cellulis 

 rotundis majusculis pluriseriatis, corticate e cellulis minimis verticalibus for- 

 mation. Cystocarpia fronde immersa, inter fila strati medidlaris suspensa, reti- 

 culo Jilorum velata, carposlomio demum aperta, fila sporifera a placenta 

 centrali emissa continentia. Sporce subrotunda, seriate. 



Areschougia australis ; stem terete at base, compressed and flattened 

 upwards, then midribbed, laxly much branched ; branches broadly 

 linear, ligulate, elongate, distantly denticulate, alternately decom- 

 pound ; ramuli constricted at base, linear-oblong, subobtuse ; con- 

 ceptacles 2-5 together in the ultimate ramuli. 



A. australis ; caule basi tereti, sursum compressa, tunc complanata et costata, 

 laxe ramosissima ; ramis late liuearibus, ligulaformibus, elongatis, denticu- 

 latis, alterne decompositis ; ramulis basi constrictis, lineari-oblongis, obtusius- 

 culis ; cystocarpiis 2-5, in ramulis immersis. 



Areschougia australis, Harv. in Trans. R. I. Acad. v. 22. p. 554. Harv. 

 Alg. Austr. Exsic. n. 384. 



Halymenia australis, Sond. Plant. Preiss. v. 2. p. 173. 



Phacelocarpus australis, /. Ag. Sp. Alg. v. 2. p. 649. 



Euctenodus australis, Kiitz. Sp. p. 770. 



Hab. Shores of Western Australia, cast up from deep water. Abundant 

 on the western shore of Eottnest Island, after storms, IF. H. H. 

 Fremantle, Mr. Clifton. Swan Eiver, Preiss, Mylne, etc. 



Geogr. Distr. As above. 



Descr. Root a thick, fleshy disc. Frond 2-3 feet long, 1-2 or 3 lines in 

 breadth, preserving a nearly equal breadth throrgl«oi<' . Main stem cylin- 

 drical near the base, soon becoming compressed, and then flattened into a 



