254 Transactions.— Botany. 
Staurastrum avicula, Brébisson. 
Mr, Archer thinks that our plant may be a distinct form and says that 
Ralfs’ figure of the English species is incorrect. I am willing to accept 
this, but as I have not seen any specimens since writing my former paper I 
am not prepared to suggest any new name. 
All these minute forms of Stawrastrum are difficult of identification and 
it would be easy to multiply species upon the slight differences occurring so 
frequently. 
Didymocladon stella, mihi. 
This plant must, I suppose, be relegated to the genus Staurastrum, as 
Pritchard, Rabenhorst and succeeding writers do not admit Ralfs' genus. 
As to its specific status, I am in some doubt. After carefully compar- 
ing it with specimens of S. furcigerum, both from Hawke's Bay and from 
England, and allowing for Rabenhorst's statement that S. furcigerum may 
have from three to nine rays in end view, I cannot regard my S. (Didymocla- 
don) stella as identical with that plant. In all my specimens of S. furcigerum, 
as remarked in the first part of this paper, whether there are five or six 
rays, those rays which are behind the terminal ones, and which are at first 
sight out of focus, are always in almost, if not quite, direct correspondence 
of direction with the terminal rays. I cannot see how in any case the pecu- 
liar multi-radiate appearanee of S. stella can be produced by the English 
plant. ; 
I find, however, in the * Midland Naturalist,” a figure (vol. iv., pl. v.) 
of Staurastrum arctiscon, Ehrenberg, a plant mentioned by Rabenhorst as 
American, under the name Xanthidium arctiscon, and seemingly found 
lately in Wales. This plant, in end view, has six terminal rays, and eight 
others behind them, almost in corresponding directions. Whether, in some 
cases, it may show the twenty-eight divaricating rays of my S. stella I can- 
not say: if so, my plant will have to be abandoned as a distinct species. 
S. pseudo-furcigerum, Reinsch, though its side view approaches best to 
that of S. stella, differs altogether in end view, being then more like S. 
eustephanum in general outline. 
I find that Mr. Archer would refer our plant rather to Staurastrum sex- 
angulare, Bulnheim, which I do not know. 
Docidium baculum, Ehrenberg. 
I expressed in my former paper doubts as to the existence of this plant 
here, and after comparison with English specimens I have come to the con- 
clusion that it is not found here, or at least that it has not come under my 
notice. Its distinctive character is the possession of a solitary, prominent | 
inflation at the base of each segment. All my New Zealand specimens 
show at least more than one inflation, 
