THE YAN YEAN RESERVOIR, VICTORIA. 69 
Long. s. spin. 32 р, c. spin. 52-56 ш; lat. х. spin. 38-44 р, с. spin, 58—66 y; 
lat. isthm. 11-5 р. (Pl. 6. fiv. 14.) 
Hub. Yan Yean Reservoir, in the plankton (Feb.-May, 19053. 
Judging by the front view only the Australian forms are unquestionably 
Staurastrum patens, W. B. Turn., but the drawing given by Turner of the 
vertieal view does not seem to me to be correct. Assuming this to be the 
case, the only striking difference between the Australian and Indian forms is 
the presence of three large spines instead of twoat each angle. The elevated 
triangular platform on the apex of each semicell is furnished with a pair of 
denticulations near each angle and within the lateral margins. This same 
variety has also been described by Playfair (under the name of * forma aus- 
байга?!) from New South Wales. 
S. patens should be compared with S. Freemanii var. triquetrum, W. < 
G. №. West ( Freshw. Alg. Ceylon,’ Trans. Linn. Soc. ser. 2, Bot. vi. (1902) 
p. 177, t. 21. fig. 22). 
S. javanicum, Gutw. (* Alg. Java, Bull. de l'Aead. Sei. Cracovie (1902) 
р. 604, Е. 39. Во. 59), does not differ sufficiently from S. patens to warrant 
separation as a distinct species. 
10. SrAvnAsTRUM UXICORXE, W. В. Turn. Le. p. 107, t. 15. fig. 16. 
Var. NODIFERUM, (W. B. Turn.) W. у G. 5. West, in Trans. Linn. Soc. 
ser, 2, Bot. vi. (1902) р. 175.—8 nodiferum, W. В. Turn. Le. р. 130, t. 14. 
fig. 20. 
Forma minor, aculeis curvatis 4-5 ad capitulos processuum ; semicellulæ 
a vertice vise lateribus subrectis et constrictione infra angulos capitatos 
prominentiore. 
Long. е. spin. 18-20 ш; lat. c. spin. 18-19 ш; lat. isthm. 4 д. (Pl. 8. 
fig. 11.) . 
Hub. Yan Yean Reservoir, at the weedy margins (Mar. 1905). 
S. unicorne appears to be а species with an eastern distribution, and the 
extension of а small form of it as far south as Victoria іх decidedly interesting. 
The extreme forms of the species are rather different in appearance, but the 
connecting forms are numerous and include a large series of intermediate 
states. 
The form under consideration is the smallest yet found, and differs from 
all other known forms in the straightness of the sides of the vertical view. 
From four to five curved aculei are attached to each capitate angle. 
47. STAURASTRUM STRIOLATUM, (Näg.) Archer, in Priteh. Infus. (1861) 
p. 740; Nordst. in Vidensk. Medd. Nuturh. Foren. Kjóbenh. (1869) p. 225, 
t. 4. fig. 45. 
Long. 21-23 р; lat. 21-24:5 u ; lat. isthm. 7-8 р; diam. zygosp. 37-39 y; 
>. =” 
crass. zygosp. 24 ш. (Pl. 6. figs. 10-12.) 
