646 
IX. ALGiE. 
Frond leaf-like, green, membranous 102. Ulva. 
Frond tubular, membranous, green 103. Enteromorpha. 
Frond filiform or expanded, purplish 104. Bangia. 
Tkibe V. Batrachospermeae. Frond blackish or olive-green or purple, filiform, inar- 
ticulate, branching, composed of small cells ; branchlets 0 or monilform. and whorled. 
Fructification moniliform strings of naked spores, forming external tufts or concealed 
in a tubular frond. — Freshwater. 
Frond nodose, with whorled moniliform branchlets .... 105. Batrachospeeaium. 
Tkibe VI. Conferveae. Frond green , of articulated filaments , consisting of cylindric 
cells, that are usually longer than broad, and are full of coloured mailer. Anthero- 
zoids minute, swarming in the cells. — Marine and freshviater. — There must be an im- 
mense number of New Zealand species to be discovered. 
Filaments tufted, branched 106. Cladophora. 
Filaments unbranched 107. Conferva. 
Filaments joined by transverse tubes 108. Tyndaridea. 
Tribe VII. Zygnemacese. Frond green, of simple articulated floating threads of ex- 
cessive tenuity, composed of cylindric cells ; cell contents of definite form. Spores large, 
green orange or vermilion-coloured, solitary, formed of the union of the contents of two 
cells, or the division of the contents of one. — Marine and freshwater Algce . — Very nu- 
merous, not hitherto collected, in New Zealand. 
Tribe VIII. Hydrodictyeae. Frond green, of cylindrical cells, uniting and forming a 
saccate network, with polygonal meshes ; each side of the mesh formed of a single cell. 
Cell contents resolving into antherozoids, which arrange themselves and form a new net- 
work within the parent cell. Network hence viviparous. — This beautiful freshwater 
group has hitherto not been detected in New Zealand. 
Tribe IX. Oscillatorieae. Fronds green, attached or floating, rarely olive-brown blue 
or purple, forming a stratum composed of simple or sparingly branched very minute 
threads ; each thread consists of a membranous pellucid sheath, enclosing an annulate 
axis of short cells. — Marine or freshwater minute Algae . — Very numerous in species, but 
hitherto hardly at all collected in New Zealand. 
Filaments attached, short, tufted, erect, branched 109. Calotiirix. 
Filaments rigid, usually floating, lying in a mucous matrix ... 1 10. Oscillatoria. 
Filaments free, branched 111. Toiapothrix. 
Tribe X. Nostochineae. Fronds olive or bright green, forming gelatinous masses, 
traversed by moniliform filaments of globose or oval cells, with here and there a larger cell 
than lice others, of whose function nothing is known. — Freshwater pools and on damp 
ground, often appearing suddenly after rain. — The species are very numerous, and have 
never been collected or studied in New Zealand. 
Filaments unbranched 112. Nostoc. 
Tribe XI. Qesmidieae. Microscopic unicellular green Algce. Cell-wall membranous. 
Propagation by the cell contents becoming divided in the middle, and a new half-cell 
being formed at the medial line . — Very minute marine or freshwater Algce, either para- 
sitic or forming floating masses, usually occurring amongst other Conferva. — The tribe 
is a vast one. 
Tribe XII. Diatomese. Microscopic unicellular, yellow-brown Algce ; cell orbicular 
triangular or of very various symynetric forms ; cell-wall siliceous. Propagation as in 
Desmidiese. — Microscopic Alga, marine or freshwater ; the siliceous coat of the cell is 
often exquisitely sculptured, and is a beautiful microscopic object. — The genera and 
species are extremely numerous , and subject of special study . Dr. Lauder Lindsay has 
published a catalogue of New Zealand species ( see Journ. Linn. Soc. ix. 129). 
