Presuming that few persons will think of collecting seaweeds much earlier than the month of May, let me observe that most of the accessible species of olive and green plants which grow on rocky shores and in tide-pools, will be found from May to June in pretty fair condition, but very few red plants, except those which grow on the shady sides of rock-pools, or under the shelter of the larger olive weeds, will be met with until a considerable space is laid bare by the receding water at the low spring tides, about a day or two before and after the full moon. As nearly all the _rare_ red weeds grow in deep water, they are seldom taken in any degree of perfection unless they are dredged; but in the summer months, say from June to the end of August, many fine plants are occasionally thrown up from deep water, and others are found growing on the stems of the great oar-weeds, portions of which are cast ashore, beautifully fringed with one or more species of Delesseria and other rare Rhodosperms--in fact, during the rising tide, diligent collectors may secure many a lovely deep-water plant as it comes floating in, but which, if allowed to remain long exposed to the action of sunlight, will fade in colour and decompose before it can be mounted. This is especially the case with all the soft gelatinous red plants, such as the Callithamnia, and all the Gloiocladiæ, as well as a few of the softer olive weeds; and here I may observe that there is one genus of beautiful olive plants, the _Sporochnaceæ_, which must on no account be put into the vasculum with any of the delicate red plants, for they not only very rapidly decompose, but injure almost all others with which they are placed in contact. The species are not numerous, and they may be easily recognized, after having been previously studied from the coloured figures either in Harvey's 'Phycologia,' or in Bradbury and Evans's 'Nature-printed Seaweeds.' It is also a curious fact respecting this genus, that while they are all of a beautiful olive tint in the growing state, they invariably change to a fine verdigris-green in drying; and indeed this is very generally the case with the filamentous olive weeds, the Fuci, or common rock-weeds, as constantly turning quite black after mounting: whence the term, that of "Melanosperm," which is given to the subdivision to which all the olive weeds belong. As there are so few seaweeds which have generally known common names, I shall make no apology for using the names by which they are known to science, presuming that all intending collectors will, as I have already suggested, gain _some_ knowledge of Terminology ere they go out "seaweeding."