74 CONFERVACEiE. 



Matted tufts an inch or more in diameter, sometimes widely spreading. Filaments 

 scarcely an inch long, rising from creeping fibres, sparingly branched, flaccid, the 

 branches very irregular, few or many, either undivided or once or twice compounded, 

 naked, or having a few secund ramuli toward the ends. Articulations^ especially the 

 lower ones, very many times longer than broad, their membrane thin and membranous. 

 Colour a very pale green, with watery endochrome. 



This has the densely matted habit of the preceding species, but the filaments of which 

 the mats are composed are much more robust, and less rigid, of a paler green, &c. 

 Kiitzing well observes tliat it has the aspect of a Valonia. 



** RUPESTRES ; rigid, dark-green, tufted ; the cell-wall thick. 



3. Cladophora rupestris, L.; filaments capillary, rigid, dark-green, straight, tufted, 

 bushy ; branches erect, crowded, densely clothed with appressed, opposite or tufted, 

 subulate ramuli ; articulations three or four times as long as broad. Linn. Sp. PI. p. 

 1637. Dillw. Conf. t. 23. E. Bot. t 1699- Harv. Phyc. Brit. t. 130. Kiltz. Sp. 

 Alg. p. 396. Wyatt, Alg. Danm. No. 95. 



Hab. Rocky shores, near low water mark. Fiskernaes, near Cape Farewell, 

 Greenland, Br. Sutherland. Halifax, W. H. H. (v. v.) 



Root a largish disc. Filammts densely tufted, 2-6-8 inches long (in my American 

 specimens scarcely two inches), capillary, rigid, very dark -green, much branched ; the 

 branches straight and very erect, repeatedly divided, the divisions either alternate or 

 opposite. Penultimate branches often nearly naked, filiform, elongated, very erect and 

 straight ; in luxuriant specimens set throughout with opposite or fascicled or scattered 

 subulate ramuli, whose terminal cell is sometimes acute, sometimes obtuse. The process 

 of cell division is well illustrated in this species, and may be observed even in dried 

 specimens, so perfectly does the endochrome recover its form. The cells of the middle 

 portion of the branches divide as well as those of the younger ramuli, and consequently 

 consecutive cells are found of various lengths. 



Two specimens of what I take to be a much denuded and battered state of this species 

 were collected by Dr. Sutherland, in the Arctic expedition under Captain Inglefield, in 

 the above mentioned locality, and have been sent to rac by Professor Dickie of Belfast. 

 They are faded to a dull green. The substance and ramification, so far as branches 

 remain unbroken, are those of C. rujKstris ; but in one specimen the articulations are 

 very short, being only as long as their diameter, or scarcely longer. This peculiarity 

 at first seems sufficiently characteristic of a distinct species, but a little further exami- 

 nation shows that the character is deceptive, resulting merely from the ordinary 

 process of cell-division being in this specimen carried to an excess. On the other 

 specimen are cells of the common length mixed with these short or halved cells ; 

 and intermediate stages occur which quite explain the unusual character of the first 

 specimen. 



