Lamarck, Schweigger, and other naturalists, however, reasoning from what is known of other compound animals, deny the existence of this locomotive power in these zoophytes; "and there is little doubt," says Dr. Johnston, "that these authors are right, for, when placed in a basin of sea water, the _Pennatulæ_ are never observed to change their position; they remain in the same spot, and lie with the same side up or down, just as they have been placed. They inflate the body until it becomes to a considerable degree transparent, and only streaked with intercepted lines of red, which distend at one place and contract at another; they spread out the pinnæ, and the polyps expand their tentacula, but they never attempt to swim, or perform any process of locomotion." _P. mirabilis_ is common in the east and north coasts of Scotland. The _virgularias_ differ from the _pennatula_ chiefly in their development, relative to the axis of the colony and the shortness of the pinnæ, which carry the polyps; and in this, that no spiculæ enter into the composition of its softer parts. _V. mirabilis_ is found in the North Sea, on the coast of Scotland, and as far north as Norway. In Zetland it is known as the sea-rush. It is abundant in Belfast Lough, but, from its brittle nature, perfect specimens are difficult to obtain. "It seems," says Sowerby, "to represent a quill stripped of its feathers. The base looks like a pen in this as in other species, swelling a little way from the end, and then tapering. The upper part is thicker, with alternate semicircular pectinated swellings, larger towards the middle, tapering upwards, and terminating in a thin bony substance, which passes through the whole extent, and is from six to ten inches in length." In a communication to Dr. Johnston, from Mr. R. Patterson of Belfast, commenting on Müller's figure of _Virgularia_, he tells us that in the longest specimen he had, no two plumes were precisely alike--so unlike, indeed, that the artist copying one, could not for a moment hesitate, after raising her eyes from her paper, to look at the animal, as to which she was copying. Its short waving and deeply dentated wings are of a brilliant yellow. The polyps, which appear upon their lobes, are whitish, transparent, and form a fringe of small diaphanous white stars (Figs. 62 and 63). We may figure to ourselves a slender wand-like and much-elongated polypidom, carrying only a non-contractile polyp on one side, which would give us an idea of the Pavonaria, of which we know only one species, which is from the Mediterranean.