2 Verr Brecuer Wirrrock. 
manner with the longer, cylindric cells. A more careful examination of 
the rich material, containing the plant in almost every stage of develop- 
ment, which I gathered there, has taught me, that this Cladophora-like 
alea, far from belonging to that genus, forms the type of a distinct 
order of plants, distinguished by a quite original mode of development 
and formation of spores. The order I have named Pithophoracea, and the 
only genus, as yet known, belonging thereto, Pithophora, from. médog = 
cask, and gogdés = carrying, because of the peculiarly short (spore-) cells 
mentioned above. 
From D:r P. T. Cieve, Professor of chemistry at this University, 
I have received for examination a rich material of a Cladophora-like alga, 
gathered by him in the isle of S:t Thomas in the West Indies in 1868. 
This was also found, on a more careful examination, to belong to the 
genus Pithophora, forming a new species of this genus, very clearly 
distinguished by peculiar morphological characters. 
From Professor EK. von Martens, jun:r, I received as a present, 
during a visit to Berlin in 1873, several very interesting alge collected 
during the prussian expedition to Kast-Asia in 1860—62, in which v. 
Martens was one of the participators. Among these alge occurred two, 
which were found, on a nearer examination, to belong to the group of 
Pithophoracew; one labelled Cladophora sumatrana v. Mart. (from Sumatra) 
and one Cladophora Zellert v. Mart. (collected in Japan). Both these spe- 
cies are described — though, it is true, rather succinctly — by D:r G. 
v. Martens, sen:r, in »Die preussische Expedition nach Ost-Asien. Bo- 
tanischer Theil. Die Tange.» ‘The figures attached to the treatise inti- 
mate, that this author has already observed the characteristic short (spore-) 
cells in »Cladophora sumatrana.» In »Cladophora Zeller» they have, 
however, escaped his attention. 
During a review of the numerous figures of different species of 
Cladophoree, which Kiitzing has given in his Tabule Phycologice, I 
have observed two figures constructed so as to suggest the represented 
species to belong to the new group of Pithophoracee. These two-.species 
are Cladophora Roettleri (Roth) Ktitz., represented in Vol. IV, plate 46, 
and Cladophora Oedogonia Mont., represented in Vol. VI, pl. 1. 
By the kind mediation of Professor P. T. Creve, D:r A. Grunow 
in Vienna has put at my disposal, with the greatest liberality, a consi- 
derable part of his rich collection of Cladophoree from all parts of the 
world. This collection contained, among other things, original specimens 
of Cladophora Roettleri (Roth) Kiitz.; and the examination of these 
