On the rocky bottoms of submarine tide-pools, near low-water mark, all round the coasts of Scotland and England, is a weed with narrow fronds and pinnate ones of a lance-head shape, with spiny teeth on their edges. It is a clear olive-brown plant, and gets a verdigris tint when it is exposed. It is called the ligulate desmarestia. Perhaps more beautiful, but not more interesting than these kinds of fucus, are the ulvæ, those broad, flat, wrinkled edged, green sea-weeds, looking like half-transparent membranes. One of them, the broad ulva, has a small disk by way of a root, and grows from six to twenty inches in length and from three to twelve in breadth, in tufts of different shapes. It is very common on all shores, on rocks and stones between tide-marks, and extends downward to a depth of ten fathoms. It has a wonderful geographical distribution, for, with the exception of the coldest regions of the globe, it inhabits every shore. It used to be eaten under the title of oyster green, being prepared like laver; and the Icelanders used to, and perhaps may still, ascribe an anodyne virtue to it. They bind it on the forehead in fevers, writes a Scottish botanist. The other ulva, which is nearly as common as this, is smaller, and grows in the form of an inflated bag, which opens and expands. It is of a very bright and yellowish green, and it is thinner and more delicate than the other kind. It is seldom seen except in spring or early summer, on rocks, stones, and shells between tide-marks, and it is generally distributed around British shores and those of Europe. A very common green weed, found between tide-marks and also in ditches running into the sea, was supposed by its first describers to resemble an entrail or intestine; hence it has been called Enteromorpha intestinalis, from the Greek words _enteron_, entrail, and _morpha_, form. It grows from a few inches to a foot or more in length, and from a line to three or four inches in diameter. Seen where it is attached to a stone, it is like a tube, hollow, membrane-like, and green; but further out it is larger and swells out into an irregular bag, crisped and curled here and there. It is very common all over the world, and finds its way sometimes into fresh water. The Rev. J. Pollexfen notices that it is prepared for culinary purposes by the Japanese for an ingredient in their soups.