adhering to paper. Colour a dull brownish or somewhat purplish-red ; 
becoming much darker in drying. Unless the specimens of this plant be 
allowed to remain some hours in fresh-water, they will stain the paper on 
which they may be laid, dull brown, and will themselves turn completely 
black and rigid, and refuse to adhere to the paper: by steeping, a large 
quantity of brown, offensive matter is discharged, and specimens so treated 
preserve a shade of red, and adhere to paper. 
A very rare plant on the British shores, though frequent in 
the south of Europe. I believe it was first noticed by the late 
Miss Hutchins of Bantry, who communicated specimens to Mr. 
Turner, by whom they were regarded as an articulated variety 
of Fucus cristatus, the Rhodymenia cristata of modern writers. 
That so singular a mistake should have been committed by an 
author of so much judgment and knowledge of his subject as 
Mr. Turner, only shows the imperfect microscopic examination 
to which marine plants were at that time subjected. The resem- 
blance between these species is merely an outward one; the 
structure is very different. In our modern system, therefore, 
instead of being regarded as varieties of one species, they are 
placed in widely separated genera. 
The present plant has a structure very similar to that of a 
Polysiphonia, 11 which genus I formerly placed it. Indeed, 
except that we have here an external coating of cells, there is 
nothing to distinguish it from an ordinary Polysiphonia. It is 
very closely allied to Pol. fruticulosa and P. thuyoides of authors, 
and as these are of exactly similar structure, I propose to transfer 
them also to the genus Rytiphlea, to which group ought to be 
added all completely inarticulate species of Polysiphonia. 
Our figure is made from a specimen gathered at Miltown 
Malbay, where, in one or two stations, I was so fortunate as to 
meet with this beautiful plant m considerable abundance, last 
summer. It completely clothed the rocky bottom of a tide-pool, 
four or five yards in diameter, and from three to six inches in 
depth. Where the water became deeper the plant disappeared. 
Fig. 1. RyrrpHtma compianata:—of the natural size. 2. Portion of a 
branch. 3. Portion of the surface. 4. Transverse section of the frond. 
5. Longitudinal section of the same :—all more or less magnified. 
