Ser. Riiodospermeje. Fam. Rhodomelacea. 



Plate XXL 



DICTYMENIA SONDERI, Haw. 



Gen. Char. Frond flat, membranaceous, midribbed, alternately decom- 

 pound, pinnatifid or rarely foliiferous, areolate; the medullary cells 

 large, twelve-sided, colourless, transversely set; the cortical minute, 

 irregular, coloured. Fructification: 1, ovate, stipitate ceramidia, 

 containing a tuft of pear-shaped spores ; 2, simple or branched sti- 

 chidia, containing tripartite tetraspores. — Dictymenia [Grev.), from 

 Scktvov, a net, and vf^rjv, a membrane, because the membrane appears 

 areolated (under a low magnifying power) . 



Frons plana, membranacea, costata, aUerne decomposita, pinnatifida v. raro folii- 



fera, areolata ; strato medullari ex cellidis viagnis hyalinis dodecajiedris trans- 



versim ordinatis, corticali ex cellnlis minutis coloraiis irregularibus formato. 



Fruct. : 1, ceramidia pedicellata ; 2, stickidia propria, shnplicia v. ramosa, te- 



trasporas \-2-seriatas triangule divisas foventia. 



Dictymenia Sonderi; stem shrubby, terete or winged; branches broadly 

 linear, midribbed, obtuse, irregularly bi-tripinnatifid ; pinnae and 

 pinnules subdistant, midribbed, and penninerved, strongly areolate, 

 fringed with trifid toothlike processes ; stichidia very much branched, 

 rising from the nerves. 



D. Sonderi ; caule rohusto subtereti ; ramis lato-Unearibus obtusis costatis bi- 

 tripinnatifidis ; laciniis lacimdisque distantibus costatis et penninerviis cou- 

 spicue areolatis, dentibus iri-multijidis fimbriatis ; stichidiis ramosissimis fru- 

 ticosis ex nermlis enatis. 



Dictymenia Sonderi, FLarv. Alg. Exsic. Ausir. n. 122. 



Dictymenia fimbriata, Harv. in Trans. R. I. Acad. v. 22. p. 538 (non Grev.). 



Hab. Western Australia : Garden Island, W. II. II. ; Fremantle, G. 



Clifton, Esq. 



Geogr. Distr. As above. 



Descr. Root a large, fleshy disc. Stem hard and woody at base, 1-2 lines in 

 diameter, 2-4 inches long before it branches, gradually narrower, loss te- 

 rete, and more distinctly winged upwards, and passing into the linear, main- 

 rachis of a much divided frond. The full-grown frond is 1^-2 feet long or 

 more, and several times compounded in an irregularly pinnatifid order, 

 The main branches are sub-bipinnatifid, but the pinna; are of unequal 

 length and rather distantly placed, and the strictly pinnate character is 

 therefore often lost. All the divisions of the frond issue at acute angles, 

 and are strictly linear, about 2-3 lines wide, and rounded at the top. The 

 older ones are strongly, the younger faintly midribbed, and the midrib is 



