MaskELr.—0On the New Zealand Desmidier. 239 
2. Spheerozosma, Corda. 
S. pulchrum, Bailey. S. (R. XXXV.) 
Occurs in Hawke's Bay, rarely. I have not seen it. Mr. Archer (in 
Pritch. Inf., p. 724) includes this plant in the genus Spondylosium, as it has 
no processes uniting the joints. Rabenhorst considers Spondylosium only 
a sub-genus of Spherozosma. 
8. Euastrum, Ehrenberg. 
E. ansatum, Ehrenberg. S. (R. XIV.) 
Not uncommon. From Hawke's Bay. 
4, Cosmarium, Corda. 
C. ralfsii, var. B, var. nov. 
Pig. 1. 
Differs from the normal form only in its size, which is very small. 
Length in front view, 37:5 u; breadth, 25. But these dimensions are 
quite constant, and the larger form has not been present with it in any 
gathering which I have observed. Were it not for the slightly triangular 
segments it might be C. cucumis; it cannot be C. pyramidatum, as the frond 
is smooth. 
C. thwaitesii, Ralfs. (R. XVII.) 
Fig. 2. 
Rare. 
I am doubtful about this plant, as I find no trace whatever of any gela- 
tinous covering, whether for single fronds or colonies. Ralfs says of it, 
** puncta very indistinct : the plant here is smooth. Length, 44 p. 
C. pusillum, Brébisson. 
Fig. 3. 
This is the smallest plant of the genus known to me. I copy Mr. 
Archer’s description (in Priteh. Inf, p. 731): ‘Frond very minute, 
slightly broader than long, constriction acute, segments angulato- M 
n narrowing upwards, smooth, angles rounded, ends slightly concave.’ 
I think, however, that the plant here is punctate. The plant is scarcely 
visible below a power of 200 diameters. Length of frond, 124 ; breadth, 
5 u. 
Hitherto described only from France (Brébisson) and Saxony (Raben- 
horst). 
Not common. I have specimens dividing, but no zygospores. 
C. punctulatum, Brébisson. i 
Very similar to a young state of C. margaritiferun : indeed Mr. Archer 
(in Pritch. Inf., p. 733) unites the two. Rabenhorst is doubtful on the 
point. 
Common, both in Canterbury and Hawke’s Bay. 
