THE YAN YEAN RESERVOIR, VICTORIA, 13 
Hab. Yan Yean Reservoir, т the plankton and at the weedy margins 
(1905). 
This species was originally deseribed from Ceylon, and the Australian 
specimens only differ in the less prominent denticulate warts at the apices of 
the semicells, and in the less inflated body of the semicell as seen in vertical 
view. Playfair has expressed the opinion that Staurastrum indentatum is an 
“immature form” of S. assurgens, Nordst, but he does not appear to have 
recognized the fundamental differences between these species. 
94. STAURASTRUM LONGIRADIATUM, W. у G. S. West, in Trans. Linn. Soc. 
ser. 2, Bot. у. (1896) p. 267, t. 17. fig. 23. 
Var. SUBNUDUM, var. п. (PI. 6. fig. 23.) 
Var. parte basali semicellulie. leviter subrectangulari, apice sine verrucis 
emarginatis et levissime concavo, apicibus processuum subtrifurcatis ; semi- 
cellulis a vertice visis fusiformibus, corpore elliptico. 
Long. 30-31 ш; lat. с. proc. 68-76 p : lat. isthm. 65-8 p ; crass. 11 p. 
Hab, Yan Yean Reservoir, at the weedy margins (Nov. and Dec. 1905, 
and Jan. 1906). 
This variety occurred abundantly in Dec. 1905, and also occurred in the 
collections made in the preceding and following months. The type form of 
the species was never so abundant, but at the same time it was found in the 
material from April 1905 to Jan. 1906, and occurred in plenty in the 
plankton throughout the greater part of the year. 
55. STAURASTRUM ZONATUM, Bérges. in Vidensk. Medd. Naturh. Foren. 
Ajóbenhavu (1890), p. 46, t. 5. fig. 48. 
Long. s. proc. 34 u, c. proc. 42—44 u ; lat. c. proc. 48-56 u ; lat. іх. 
10 м. 
flab, Pool in the Yan Yean catchment area, frequent (Sept. 1907). 
Previously known from Brazil, and a varietv of it from Ceylon. 
Genus SPHÆROZOSMA, Corda. 
26. SPH.EROZOSMA WaLLicnit, Jacobsen, in Botan. Tidsskrift, viii. (1876) 
p. 211. 
Forma AUSTRALIS, f. п. (РІ. 3. fig. 3.) 
Forma duplo-minor, lateribus semicellulæ rectis et parallelis eum denticulis 
prominentibus tribus. 
Long. 8 ш: lat. c. dentic. 8:5 д; lat. isthm. 4 д. 
Наб. Yan Yean Reservoir, at the weedy margins, very rare (July 1905). 
In this form the lateral margins of the semicells are quite straight and 
furnished with three dentieulations, one at each angle and one in an 
intermediate position. 
