376 
THE SEAWEEDS 
to 3 mm. wide. This principal lamina is simple or forked and set through- 
out with lateral branches or pinnae, which are furnished with a second or 
third series of lesser divisions. Form and size vary very much. Margins 
in some specimens entire, in others slightly toothed, in others deeply cut; 
either flat, undulate or curled. Apices of all branches very acute. Colour 
bright pink-red. Substance gelatinous. Distributed in many parts of the 
world. 
South Australia (Eastern Bays), Western Australia, Victoria. 
Halymenia plana Zanardini. 
Frond foliaceous, thinly membranous, incisely lobate, the lobes broad 
and obovate, the margin entire; the structure dense and compact. 
Victoria (Port Phillip). 
Halymenia (?) Muelleri Sonder. 
= N emastoma (?) gelinarioides Harvey. 
Frond 10-15 cm. wide, compressed, irregularly pinnate, rachis broad; 
pinnae attenuated, dentate at the margin, denticulations very patent, 
horizontal, not as wide as the rachis. 
South Australia (Lefevre Peninsula). 
Halymenia digit at a J. Agardh. 
Frond caespitose, globose, 12 cm. to 20 cm. across, thick, irregularly 
dichotomous, compressed, the segments above the cuneiform base expanded 
in a linear fashion, subpalmate, flabelliform ; the adult ramuli bear pro- 
liferous segments from the margin, above the narrower stipe, cuneiform, 
dilate, subpalmate, multifid. Colour purplish-red. Adheres to paper. 
Victoria (Port Phillip). 
GRATELOUPIA Agardh. 
Frond compressed, gelatinous, membranous, sometimes almost tubular, 
dichotomous, pinnate or proliferous; cortex consisting of two layers, the 
inner of articulate filaments, net-like, sometimes very anastomosed, often 
loosely so; the outer filaments moniliform, loosely or solidly united with 
mucus. Cystocarps minute, scattered over the frond or irregularly collected 
in sori, in depressions below the cortex, with filaments issuing from the 
cavities, nucleus simple, surrounded by a hyaline membrane. Tetraspor- 
angia immersed in the cortical layer, sparse, cruciate. Colour reddish- 
brown. 
Grateloupia proTifera J. Agardh. 
Frond up to 60 cm. high, .compressed, linear, elongate, very attenuated, 
regularly proliferous from the margin, irregularly proliferous from the 
pinnae, finally glabrous at the apices. Cystocarps numerous over the whole 
frond. Tetrasporangia developed on the young ramelli. 
Tasmania. 
Grateloupia gigartinoides Sonder. 
Frond membranous, at the base terete, above compressed, alternately 
bipinnate; pinnae regular, distichous, patent, elongate, sublanceolate. 
