the Mixon. It can be reached only by means of a boat, and can be examined only at low water of spring-tides, and then only (at least with any comfort) provided no sea is running, as otherwise the breakers wash over the mass, and prevent examination. A wet foot is pretty sure to be an accompaniment of the expedition, for the angular blocks, offering, here only projecting points, and there surfaces sloping in all angles of obliquity, and draped with wet and slippery beds of Enteromorphœ and other weeds, afford but a precarious foot-hold for one used to these rough rocks, and to an unpractised tread are sure to prove treacherous. In summer, however, a partial immersion in these crystal waters is an evil of no terrible magnitude.
The Laminariœ luxuriate on the shelving outer margin, and toss their broad brown fronds to and fro in the rolling seas, like forest trees that rock in the gales of autumn. But it is chiefly the red and green families of Algæ that flourish here; the Winged and the Sinuated Delesseriœ; the excessively ramified Plocamium, whose brilliant crimson trees are so much in demand by those who make mimic landscapes out of dried sea-weeds; the pencilled Polysiphoniœ; the brush-like Dasya; the feathery Ptilota; and various species of elegant Ceramia, so easily recognised by their regularly jointed stems and double incurved tips; and the tender Callithamnia, among the most delicately lovely, though the most minute of marine Algæ. Several species of Cladophora, also, here spring from the rocky surface in greater or less abundance, forming pencil-like tufts of various hues of green, some indeed dull and sombre, but others brilliantly
