OF SOUTH AUSTRALIA. 
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a psuedo-parenchymatous structure with large cells within, small cells 
without; sporangia more or less localized in somewhat swollen branchlets, 
formed at the surface, zonate; procarps present, the carpogenic branches 
of three cells on a supporting cell that forms additional corticating series, 
an inner cell of which forms an auxiliary near the carpogonium ; cystocarps 
swollen, showing, a group of filamentous cells anchoring the central mass 
to the pericarp, the carpospores formed terminally on close branched 
gonimoblasts. 
Hypnea Kutzing. 
Family PLOCAMIACEAE. 
Fronds compressed, membranaceous, pinnately decompound, the pinnules 
alternately secund in twos, threes, fours, or fives, composed of a central 
siphon, an inner layer of longitudinal oblong cells, bounded by a cortical 
layer of small assimilative cells. 
The supporting cell serves the carpogonium as auxiliary cell, and the 
gonimoblasts develop outwardly from the thallus. The carpogonium is 
three celled. After fertilization, the carpogonium and supporting cell unite, 
the supporting cell serving as an auxiliary cell. The first gonimoblast cell 
develops outwardly from the thallus and forms more thickly crowded tufts 
of branches, most cells forming carpospores. The cells surrounding the 
procarp develop into a cystocarp wall, with no special opening. 
The tetraspores are zonate and borne in special branches (stichidia). 
Plocamium Lamouroux. 
Family SPHAERACOCCACEAE (Dumont) Schmitz. 
The early development of the thallus is similar to the Plocamiaceae, and 
a system of short filaments forms around the thallus. The central filament 
is formed of a crowd of rhizoids. The cortex is well developed and dif- 
ferentiated into a large-celled inner region and a small-celled outer region. 
In Stenocladia the rhizoidal formation is considerably greater than in 
Sphaerococcus, and therefore in Stenocladia a strong medullary tissue is 
formed. 
As in the Plocamiaceae , the supporting cell serves the carpogonium as 
auxiliary cell, and the gonimoblasts develop outwardly from the thallus. 
After fertilization the supporting cell and carpogonium unite and gonimo- 
blast filaments are formed. In Sphaerococcus only the end cells of the 
gonimoblasts form carpospores, but in Stenocladia the end cells divide into 
four, each forming a carpospore, while in Phacelocarpus the three or four 
outer cells of the layer of gonimoblast tissue produce carpospores. In 
Sphaerococcus the cystocarp wall is completely closed, but has a distinct 
opening in Phacelocarpus and Stenocladia. In both of the latter genera the 
cystocarps are produced on special ramuli. 
Phacelocarpus Endl. and Dietrich. Stenocladia J. Agardh. Nizymenia 
Sonder. 
