OF SOUTH AUSTRALIA. 
265 
byssoid fibres; multifid in full-grown fronds; byssoid fibres eventually shed. 
Articulations only visible in the ramuli, bistriate, one to one and a half 
times as long as broad. Tetraspores immersed in distorted ramuli. Cysto- 
carps urceolate, tapering to a subacute apex, sessile on the sides of the 
ramuli. Colour a dark red-brown. 
South Australia (Eastern Bays, Encounter Bay), Tasmania, Victoria. 
Polysiphonia longissima J. Agardh. 
De Toni Syll. Alg. IV., 9U6. 
Frond 15-20 cm. long, filiform, sparsely pinnate, irregularly branched; 
ramuli sparse, formed on every side, naked below, subulate above, scattered 
with minute spines. Four .central siphons, corticate with striate elongate 
cells to the apices of the branches. Stichidia minute, single or in small 
subfasciculate clusters, fusiform, articulate; articulations always longer 
than broad ; tetraspores towards outside of stichidia, not prominent. Colour 
purple. 
Southern Australia. 
Polysiphonia hystrix Hook. fil. et Harvey. 
Harv. Nereis Austral, p. 41, t. XIV. ; De; Toni Syll. Alg. IV., 906. 
Frond setaceous, cartilaginous, inarticulate, branching vague or sub- 
dichomotous ; branches long, far apart, and remarkably arched ; smaller 
branches patent, similar, all covered with multifid ramuli for their whole 
length ; ramuli short, subulate, spinose, more compound when fully grown, 
usually with the apex prolonged beyond the branching part into a subulate 
acumination. Tetraspores lying to the side of ramuli. Cystocarps laterally 
inserted on the ramuli. This species is closely allied to P. Hookeri, but 
presents a quite different aspect, as shown in the figures. 
South Australia (Encounter Bay, Eastern Bays, Holdfast Bay), Western 
Australia, Tasmania. 
Polysiphonia Mallardiae Harvey. 
Harv. Nereis Austral, p. 40, t. XIII. ; De Toni Syll. Alg. IV., 908. 
Frond 15 cm. to 20 cm. long or more, about 1 mm. thick, branched with 
greater or less regularity in an alternately pinnate or bipinnate manner. 
Lower stem and branches naked and smooth, upper portion and all branches 
and pinnulae densely clothed with short, quadrifarous, imbricated, multifid 
ramuli; ramuli about 2 mm. long, rigid, patent or horizontal, irregularly 
dichotomous, the only parts showing articulations; articulations as long 
as broad, bistriate, with obscure dissepiments. Tetraspores immersed in 
the scarcely distorted upper ramuli, in a single row. Cystocarps ovate- 
urceolate, with a. slender protruding mouth, sessile on the ramuli. Colour 
in the dry state intensely black. Closely related to P. Hookeri. 
South' Australia (Eastern Bays), Western Australia, Tasmania, New 
Zealand. 
Polysiphonia Daveyae Reinbold. 
Reinb. Meeresalgen von Inv. Str. (1889) n. 49, n. 97; De Toni Syll. 
Alg. IV., 913. 
Frond tall (15-20 cm.), laterally branched, corticated to the smaller 
branches, four siphoned ; about 1 mm. thick at the base, rigid; flexible 
