As each individual separates from the community of which it has made a part, it reverses its position, and, instead of turning the margin of the disk upward, it turns it downward, thus bringing the mouth below and the curve of the disk above. These free individuals have been described under the name of _Ephyra_. This is the third phase of the existence of our Jelly-Fish. It swims freely about, a transparent, umbrella-like disk, with a proboscis hanging from the lower side, which, to complete the comparison, we may call the handle of the umbrella. The margin of the disk is even more deeply lobed than in the Hydroid condition, and in the middle of each lobe is a second depression, quite deep and narrow, at the base of which is an eye. How far such organs are gifted with the power of vision we cannot decide; but the cells of which they are composed certainly serve the purpose of facets, of lenses and prisms, and must convey to the animal a more or less distinct perception of light and color. The lobes are eight in number, as before, with a tube diverging from the centre of the body into each lobe. Shorter tubes between the lobes alternate with these, making thus sixteen radiating tubes, all ramifying more or less. [Illustration: Ephyra of Aurelia flavidula.] [Illustration: Aurelia flavidula, the common white Jelly-Fish of our sea-shores, seen from above: c, mouth; eeeeee, eyes; mmmm, lobes or curtain of the mouth in outlines; ooo, ovaries; ttt, tentacles; ww ramified tubes.] From this stage to its adult condition, the animal undergoes a succession of changes in the gradual course of its growth, uninterrupted, however, by any such abrupt transition as that by which it began its life as a free animal. The lobes are gradually obliterated, so that the margin becomes almost an unbroken circle. The eight eyes were, as I have said, at the bottom of depressions in the centre of the several lobes; but, by the equalizing of the marginal line, the gradual levelling, as it were, of all the inequalities of the edge, the eyes are pushed out, and occupy eight spots on the margin, where a faint indentation only marks what was before a deep cut in the lobe. The eight tubes of the lobes have extended in like manner to the edge, and join it just at the point where the eyes are placed, so that the extremity of each tube unites with the base of each eye. Those parts of the margin filling the spaces between the eyes correspond to the depressions dividing the lobes or scallops in the earlier stage, and to those radiate the eight other tubes alternating with the eye-tubes, now divided into numerous branches. Along each of these spaces is developed a fine, delicate fringe of tentacles, hanging down like a veil when the animal is at rest, or swept back when it is in motion. In the previous stage, the tubes ramified toward the margin; but now they branch at or near their point of starting from the central cavity, so extensively