Ser. RHODOSPERMEiE. Earn. Cri/ptonemiacece. 



Plate CXXXIIL 



HALYMENIA SACCATA, Haw. 



Gen. Char. Frond terete, compressed or flat, gelatinoso-membranaceous, 

 dicliotoraous or piniiatifid, composed of two strata; the medullary 

 stratum formed of a few, laxly interlaced, branching filaments, lying 

 in gelatine; the cortical membranous, formed of minute, coloured 

 cellules. Fructification: \, favella immersed in the frond, sus- 

 pended under the peripheric stratum ; 2, cruciate tetraspores, scattered 

 through the surface-cellules. — Halymenia [Ag.), from aA,?, the sea, 

 and viirjv, a membrane. 



F?'ons teres, compressa v. plana, gelatinoso-membranacea, dichotoma v. vage 

 pinnatijida, stratis duobiis composlta; strata medullari ex fills paucis laxe in- 

 tricatis ramosis succo gelatinoso iminerm, peripherico viembranaceo cellulis 

 minutis coloratis formato. Fruct. : l,favella frondt Immersce, infra stratum 

 periphericum suspenses ; 2, tetrasporce sparscB, cruclatim divisce. 



Halymenia saccata ; frond cylindrical, saccate, hollow, vaguely decom- 

 pound; branches constricted at their insertion, simple, bag-like, ta- 

 pering to a blunt extremity. 



H. saccata ; frotide cyllndracea saccata cava vage decomposita ; ramis ramu- 

 llsque basi arete constrictis simpUcibus saccatis sursum atteiiuatis obtusius- 



Halymenia saccata, Rarv. in Hook. Ft. Tasm. v. 2. p. 327. 



Hab. Georgetown, Tasmania, W. Archer, Esq. 



Geogr. Distr. Tasmania. 



Descr. Root discoid. Frond 8-3 2 inches long, |— f inch in diameter at the 

 thickest part, tapering to base and apex, quite simple, bag-hke, hollow or 

 filled with loose gelatine, the walls delicately and softly gelatinoso-merabra- 

 naceoiis. This primary frond emits irregularly from its sides numerous 

 secondary fronds or branches of similar character; and these throw out 

 small tertiary fronds or ramnli, also similar, until, in full-grown specimens, 

 the general h'ond becomes irregularly much-branched and dendroid, or ra- 

 ther, " cactoid." No order of ramification is followed, and the lesser divi- 

 sions may with equal propriety be described as branches, constricted at 

 their insertion, or as proliferous repetitions of a simple primary frond. All 

 the divisions taper to the extremity, which is either perfectly blunt or sub- 

 acute. The tvalls of the tubular fronds are formed of horizontally placed, 

 radiating, dichotomous strings of cellules, lying imbedded in transparent 

 gelatine : they seem to rise from the remains of a network, which, probably. 



