OF SOUTH AUSTRALIA. 
125 
RHODOPHYCEAE (Red Seaweeds). 
Subclass PROTOFLORIDEAE Rosenvinge. 
Morphological alternation of generations not present, the plants being 
either entirely non-sexnal, or consisting of monoecious or dioecious gameto- 
phytes, the zygote representing the sporophyte: protoplasmic continuity 
between cells not evident. No true trichogyne. 
Order BANGIALES Schmitz and Hauptfleisch. 
The only Order with the characters of the Subclass. 
Family BANGIACEAE Zanardini. 
Thallus (Australian) erect, filiform or foliaceous, cells with intercalary 
growth, each containing a single axial stellate chromatophore, with a large 
central pyrenoid, without pores in the crosswalls. 
Frond filiform Bangia Lyngbye. 
Frond foliaceous Porphyra 
C. Agardh. 
BANGIA Lyngbye. 
Frond gelatinous, filiform, attached at base, cylindrical or constricted, 
densely tufted, at first consisting of a single row of cells, later becoming 
several cells in thickness. Reproduction non-sexual by means of mono- 
sporangia (undivided tetrasporangia) and sexual by antheridia and oogonia. 
Bangia fusco-purpurea (Dillw.) Lyngbye. 
Growing gregariously in red patches on faces of rocks near high water 
mark. The threads are 2 cm. to 10 cm. lbng, 18 /x to 60 /x diameter. Red 
when growing, dark-purple on drying. Widely distributed in temperate 
waters of both hemispheres. 
PORPHYRA C. Agardh. 
Fronds erect, foliaceous, thin, fiat, gelatinous, mostly monostromatic, 
attached by a disc formed by the cells near the base growing downwards in 
the way of rhizoids; entire or lobed or laciniate, often undulate at the 
margin. Colouring matter phycoerythrin, characteristic of the higher 
Rhodophyceae, and phycocyanin, characteristic of the blue-green Cyano- 
phyceae. Sexual reproduction by means of motionless sperms and eggs 
which do not project a true trichogyne, the zygote dividing into 4 to 8 
spores; non-sexual reproduction by monosporangia (undivided tetra- 
sporangia). A genus abounding in cold climates and purely marine. It 
supplies more food for man than any other alga. 
Porphyra umhilicalis (L.) J. Agardh. 
The common species in Australia, occurring from Sydney round the 
southern coast to Fremantle, and in Tasmania and New Zealand, has been 
identified by E. S. Barton (Mrs. Gepp) of the British Museum of Natural 
History as being identical with the P. umhilicalis of the Atlantic and North 
