The _Cladophoræ_ are also stated to be very suitable, _C. rupestris_ being a very useful plant for the purpose. It is of a bluish-green, that harmonizes well with the tone of the sea-water, and fills up little chasms in the artificial rocks with very good effect, especially in contrast with the reddish-purple tufts of _Polysiphonia arceolata_, which do well in an Aquarium, and are a great aid to the foliage of the little marine landscape. The elegant, fan-formed, and brightly-radiated _Padina pavonia_ is likewise mentioned, and should at all events be tried, as the tufts of that graceful marine plant form very singular as well as beautiful objects in the tank.[2] [Footnote 2: A list of the plants with which Mr. Gosse furnished his first Aquarium is given in Chapter III.] I would also recommend the trial of all the plants delineated in the five Plates devoted to the sea-weeds in this little book. In Plate I., the first, occupying the upper part, with leaf-like fronds of transparent crimson, is the beautiful and not uncommon sea-weed, _Delesseria sanguinea_. The delicate pale plant below, to the right, is _Punctaria latifolia_, thin as tissue-paper, and speckled over its pale-buff surface with bright but minute grains of black. To the left is a branch of _Chordaria flagelliformis_, the rich olive of which contrasts well with the red kinds of _Algæ_. In the front, growing on a detached pebble, is the Lichen-like _Hildenbrandtia rubra_, the rich carmine of which might be made to form an exquisite touch of colour, if tastefully placed in the Aquarium; and to the extreme right is a small tuft of _Vaucheria submarina_. In Plate II., the principal object, near the top of the Plate, is a bush of _Callithamnion arbuscula_, which receives its name from the tree-like aspect which it assumes more distinctly than any other of the marine _Algæ_. Behind it, to the right, are the tall and graceful forms, with their crimped edges, of the slender _Laminaria phyllitis_. And below, still to the right, is a branch of _Codium tomentosum_, distinguished by its light, vivid green, and the edging of delicate ciliæ, which have the appearance of a border of paler green, to every branchlet. Still to the right, in the extreme foreground, is a broken piece of rock on which plants of the curious _Leathesia Berkleyi_ have grown, like convex kernels of bronze. To the left are the red-violet tufts of the _Bangia fusco-purpurea_, and behind them, a branch of _Bryopsis plumosa_. [Illustration: PLATE II. 1. Bangia fusco-purpurea. 2. Codium tomentosum. 3. Bryopsis plumosa. 4. Callithamnion arbuscula. 5. Leathesia Berkleyi. 6. Laminaria phyllitis.]