2 Veit Brecher Wittrock. 



manner wth 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 tanght me, that this Cladophora-\ike 

 alga, far from belonging to that genns, forms the type of a distinct 

 order of plants, distingnished by a quite original mode of development 

 and formation of spores. The order I have named Pithophoracece^ and the 

 only genus, as yet knov^n, belonging thereto, Pithophora^ from nCiyoç = 

 cask, and (poqôç = carrying, because of the peculiarly short (spore-) cells 

 mentioned above. 



From D;r P. T. Cleve, Professor of chemistry at this University, 

 I have received for examination a rich material of a Ciadopliora-Wke 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 E. von Martens, jun:r, I received as a present, 

 during a visit to Berlin in 1873, several very interesting algas collected 

 during the prussian expedition to East-Asia in 1860 — 62, in which v. 

 Martens was one of the participators. Among these algas occurred two, 

 which were found, on a nearer examination, to belong to the group of 

 Pii/iOjj/ioracert^; one labelled Cladophora sumatrana v. Mart, (from Sumatra) 

 and one Cladophora Zelleri 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 y)Clado])hora sumatrana.y> In ^Cladophora Zellerh they have, 

 however, escaped his attention. 



During a review of the numerous figures of different species of 

 Cladophoreœ^ which Ktitzing has given in his Tabulœ Phycologicaî, I 

 have observed two figures constructed so as to suggest the represented 

 species to belong to the new group of Pithophoraceœ. These two species 

 are Cladophora Roettleri (Roth) Kiitz., represented in Vol. IV, plate 46, 

 and Cladophora Oedogonia Mont., represented in Vol. VI, pi. 1. 



By the kind mediation of Professor P. T. Cleve, D:r A. Grunow 

 in Vienna has put at my disposal, with the greatest liberality, a consi- 

 derable part of his rich collection of Cladophoreœ from all parts of the 

 world. This collection contained, among other things, original specimens 

 of Cladophora Roettleri (Roth) Kiitz. ; and the examination of these 



