166 BTNOP8I8 OF EKITISLT SEAWEEDS. 



more distant and simple, thejointa longer, and the subs 



firm and rigid. Still specimens frequently 

 which seem to conned the two, 



296. nuda {The naked Oladophora) j filaments somewhat 

 alender, very straight, dull-green or olivaceous (when dry), 

 Bparing] j diohotomous ; ramuli few and scattered, appressed. 

 the uppermost often opposite; articulations many tunes 

 longer than broad, Hdrv. Man. ed. 2. p. 101. (Atlas, 

 PI. LXYI. Fig. 307.) 



Conferva nuda, II ore 



Hah. On basalt rocks, between tide-marks. 



My knowledge of this species, if the plant be entitled to 

 rank as a species, is confined to a specimen collected by 

 Mr. XToore, many years ago, on the coast of Antrim, and 

 now preserved in the Dublin University Herbarium. It 

 is undoubtedly nearly related to C. rupestris, from which, 

 at first sight, it differs by its duller colour and more naked 

 branches, and especially by the much longer articulations 

 of the stem, and the wider borders of the tube. Still, I 

 fear this character of long joints, which is the strongest of 

 those mentioned, is not to be altogether counted on ; for 

 though I have not observed the joints in any specimen of 

 C. rupestris to be of the extreme length of those of C. 

 nuda, yet I have seen a tendency in some specimens of 

 that species to produce long joints ; and this, joined to the 

 non- occurrence in recent times of C. nuda, has latterly 

 disposed me to consider it a variety of C. rupestris. 



297. rupestris {The rock-inhabiting Cladophora) ; filaments ca- 

 pillary, rigid, dark-green, straight, tufted, bushy ; branches 

 erect, crowded, densely clothed with appressed, opposite 

 or tufted, subulate ramuli ; articulations three or four times 

 longer than broad, Ktz. Phi/. Gen. p. 270. (Atlas, PI. LX I V . 

 Fig. 299.) 



Conferva rupestris, Linn. C. glauca, Roth. C. virgata, Roth. 

 II ab. On rocks in the sea, between tide-marks ; also beyond the 

 limits of low water. Annual. Summer and autumn. 

 A very beautiful plant, when well grown, common on all 

 our rocky shores, and extending through the whole of the 

 littoral zone, even into the belt of the Laminarice. Spe- 

 cimens gradually increase in luxuriance, and in the purity 

 and depth of their colour, as their habitat is remote from 

 high water; and those which are collected in deep rock- 

 basins, at the verge of the tide, are remarkably handsome. 



