OF SOUTH AUSTRALIA. 
27 
CLADOPHORA Kuetzing. 
A genus out of which many species have been made, both of fresh water 
and marine forms. All consist of usually much branched filaments 
articulated throughout in chains of cells. Each filament is made up of a 
single row of cells. These cells are cylindrical, with conspiduous 
chlorophores, and are multinucleate. 
Both non-sexual and sexual reproduction takes place. Non-sexual 
zoospores arise within the vegetative cells in large numbers, and escape by 
a round orifice; they have four cilia. The sexual gametes arise in the 
same way, have two cilia, and show a red spot. The sex of the gametes is 
indistinguishable but they conjugate in pairs, and form a zygote, which 
at once begins to germinate into a vegetative thallus like the mother plant. 
In some species a chain of cells, endowed with thicker walls and denser 
granular contents, separates off and becomes a cyst which, after a period 
of rest, grows out into a new frond. 
Most of the Cladophoras, of world-wide distribution, are bush-like plants, 
the branches growing out into the water free from one another, but some 
form globular, cushion-like or sponge-like masses, which cover the site to 
which they are attached, and the branches of which are closely interwoven. 
Doubtless many forms of both groups will be found on the South Aus- 
tralian coasts, as well as others in fresh water, but so far only four kinds 
have been recorded, all from the first group. 
These are C. valonioides and C. nitidula (originally described by Sonder 
from Western Australia) and two other species which Reinbold ventured 
to create from the material forwarded to him by Miss Nellie Davey and 
Dr. Engelhardt. 
Cladophora valonioides Sonder. 
Densely tufted and bright green, more or less dichotomously branched, 
often with verticils of 3 or 4 branches in the upper parts; the cells are 
cylindrical, somewhat inflated, in the branches 6-8 and in the ramelli 4-5 
times as long as broad, all constricted at the nodes; the ultimate segments 
are elongate-ellipsoidal and very obtuse. It grows to a height of 8 to 25 
cm. in moderately deep water. 
Cladophora nitidula Sonder. 
'Filaments setaceous, erect, bright green; the ultimate branchlets sub- 
secund and very short; cells cylindrical, 3-6 times as long as broad. 
Rcinbold removed these two species to the genus Siphonocladus, 
associated with Valonia. This genus is diagnosed by a branched, saccate 
or filiform thallus, arising from a cell at first continuous and afterwards 
