CHLOROSPERMEZ. 9 
Ulwa linza (Fig. 6), a beautiful and very graceful species, though by no 
means rare, is not so abundant as the former plant. It grows in similar 
situations, and sometimes even in society with it. The plant consists of a 
cluster of fronds from 6in. to 2ft. in length, about lin. in width, and 
tapering gradually to the base. The fronds are generally very much curled 
and waved at the margin, and the whole plant is of a bright grass-green 
colour. The frond of this species consists of two delicate membranes, the 
cells of which are divided vertically and shorizontally, so that they are at 
once leaf-like and tubular. To ordinary observers, this plant bears a 
strong resemblance to Enteromorpha intestinalis; and, indeed, Dr. 
Greville, of Edinburgh, in describing this species, points out the fact of 
its double membrane, forming at least a transition to the genus Entero- 
morpha. Collectors, however, after a very little practice in comparing 
specimens of these plants, will not have much difficulty in distinguishing 
them ; Enteromorpha intestinalis being always tubular and somewhat con- 
stricted at intervals, while Ulva linza is comparatively flattened, never 
constricted, and always more or less waved at the margin. Porphyra 
laciniata bears a striking resemblance to Ulva latissima, not only in out- 
ward form, but in its fructification, which consists of sori or groups of 
spores. Under the microscope the whole membrane of the plant appears 
to be divided into segments or square groups of cells, regularly arranged 
in fours, and within these squares are contained four purple spores, as seen 
in the illustration (Fig. 4). Porphyra, under the name of laver, is boiled 
and eaten with lemon juice or vinegar, and is not only very wholesome, but 
agreeable in flavour, and were it not for the ignorance and prejudice which 
sailors exhibit concerning things they know not, this common seaweed 
might become a valuable article of vegetable diet to the crews of whaling 
vessels and voyagers in the Artic regions, since nearly every marine rock 
is clothed with its dark brown fronds. The plant in our illustration 
(Fig. 7) is Porphyra vulgaris, a much more elegant species, being narrower, 
much longer, and very gracefully waved and curled at the margin, some- 
what like Ulva linza. The colour of Porphyra is a very singular departure 
from the ordinary green tint of the Chlorosperms; the plants of this genus 
being, in the living state, of a dark brown, which after drying and mounting 
on paper changes gradually to a fine purple, or sometimes to a rose red. 
The order Ulvacee contains a genus of interesting plants which at 
present must be merely glanced at, for in the first place they are, with the 
exception of one species, nearly microscopic, and, secondly, anything like a 
description of them will necessitate illustrations, most of which would be 
too minute for the purpose I have in hand, viz., popular information. I 
will merely state, then, that the genus to which I refer is named Bangia, 
in honour of Hoffman Bang, a Danish botanist. All the species of Bangia 
are purple, or sometimes inclined to brown-red, and they are mostly 
parasitic on other algz ; one species, and that the largest, being found 
near high-water mark, growing on rocks and wood. Its name is Bangia 
fusca-purpurea. Inexperienced collectors would hardly imagine this plant 
