OF SOUTH AUSTRALIA. 
375 
Family GRATELOUP1ACEAE Schmitz. 
HALYMENIA J. Agardh. 
Frond terete, compressed or flat, gelatinoso-membranous, dichotomous 
or pinnatifid, composed of two strata ; the medullary stratum formed of 
a dew, laxly interlaced, branching filaments, lying in a gelatinous matrix; 
the cortical membranous, formed of minute, coloured cellules. Cystocarps 
immersed in the frond. Tetraspores scattered through the surface- 
cellules. 
Halymenia Harvey ana J. Agardh. 
= Halymenia Floresia Agardh. 
Frond softly membranous and slippery, flat, stipitate, elongate, pin- 
nately decompound; the pinnae and pinnules broadly linear, acuminate, 
spreading, either entire or serrato-lacerate and ciliate. 
Attachment a minute disc. Frond rising with a slender, compressed, 
linear stipe, that soon becomes cuneiform and gradually passes into the 
base of a broadly linear principal lamina 15 cm. to 50 cm. long and 1 mm. 
Fig. 188 . — Halymenia Harveyana : a, plant; b, section 
of the frond. (After Harvey.) 
