OF SOUTH AUSTRALIA. 
85 
hh. Fronds with prominent midrib (cos- 
tate). Fronds dichotomous. Spores 
scattered over each face of the 
frond. Tetraspores collected into 
sublinear sori Haliseris Targ. Tozz. 
gg. Terminal cells of the frond converging 
towards a central initial cell. 
i. Frond ecostate. 
j. Reproductive cells borne on the 
frond proper. 
k. Frond consisting of a median 
monostromatic layer of large 
colourless cells covered on 
each face by a cortical layer 
of small coloured cells . . . Dictyota 
Lamouroux. 
kk. Frond consisting of a median 
monostromatic layer of large 
colourless cells, an inter- 
mediate stratum of several 
layers of cells, and a cortical 
monostromatic layer of small 
coloured cells 
kkk. Frond consisting of a median 
di- or poly-stromatic stratum, 
covered on each side by a 
cortical layer of small 
coloured cells 
jj. Reproductive organs borne in 
numerous tongue-like prolif- 
erations from the whole frond 
ii. Frond coalescent, the lower divisions 
ribbed 
Pachy dirty on 
J. Agardh 
Diiophus 
J. Agardh. 
Glossophora 
J. Agardh. 
Lobospira 
Areschoug. 
GYMNOSORTJS J. Agardh. 
Frond flat, prostate below., then ascending, fan-shaped with lobes. Sori 
on the upper face subzonate, naked, without accompanying paraphyses. 
Stupose at the base. Both Australian species are 5 to 7.5 cm. high 
and of the same or greater breadth. They are gregarious and often cover 
a considerable face of rock. 
