MasxErr.—On the New Zealand Desmidiex. 245 
At first sight this plant might be taken, in side view, for S. spinosum, or 
in end view for S. monticulosum, Brébisson. But it differs from the former 
in having its outer edges less turgid than the inner and in its processes not 
being on the same plane ; from the latter in the more cylindrical lateral 
processes and their forked tips. The nearest resemblance to it is, I think, 
S. (Desmidium) eustephanum, Ehrenberg, an American plant, referređ to by 
Ralfs, p. 215, without figure, and described and figured in Pritchard’s Infus., 
p. 748 and pl. ii., fig. 8. The differences are that in the New Zealand 
plant the sides, in end view, are emarginate and not rectilinear as in the 
American variety, and the lateral processes project beyond the sides, 
whereas in Pritchard’s figure they are very small and do not reach the 
sides. In S. senarium, Ehrenberg (also American), similar processes pro- 
ject, but there is also a second series of six others, shorter and in almost 
corresponding directions, behind the first. In the ** Midland Naturalist,” 
vol. iv., pl. v., Mr. A. W. Wills figures S. pseudofurcigerum, Reinsch, not 
unlike our plant in end view, but it is covered with minute spines on the 
processes as well as on the frond, and the side view is also different. 
On the whole, I take this plant to be intermediate between S. eustepha- 
num and S. senarium. 
is clepsydra, Spencer (in lit. cum specim.), sp. nov. 8. 
Fig. 12. 
1g. 
Frond somewhat large, smooth. Segments in side view broader than 
long, widening rapidly from the constrietion which is not deep. The ex- 
ternal edges are either straight or oftener slightly concave: lateral edges 
convex. Ultimate angles ending in a fine awn or muero. In consequence 
of the shallow constriction the segments are closely united at the base, the 
junction is broad, and there is no isthmus or band whatever. The apex of 
the third angle with its awn is usually visible beyond the external edge of 
each segment. 
Frond in end view triangular; the sides equal, slightly concave : some- 
what mammillate at the angles which are terminated by the awns. The 
concavity of the sides is not always conspicuous. 
Frond quite free from puncta. 
I have seen no zygospores attached to fronds, but in every gathering 
there are a number of bodies which may not improbably belong to this 
plant. They resemble generally those of S. dejectum, but have fewer spines. 
I have been able to compare them not only with Ralfs’ figures of S. dejec- 
tum, but also with zygospores of that species in my English gatherings. 
Length of frond in side view 31-40 » ; breadth at external edge of seg- 
ments (exclusive of awns) 80-35 p; breadth at constriction 15-17 p; side of 
triangle in end view 30-35 p ; length of awn 5 p. 
