ANTHOZOA ASTEROIDA Gorgonidae - The generic characters of Gorgonia are thus described by Johnson. "Polype, mass rooted, arborescent, con sisting of central axis, barked with a polypiferous crust ; the axis, horny, continuous, and flexible, branched in co-equality with the polype mass ; the crust when recent, soft and fleshy, when dried, porous and friable ; the orifices of the polype cells, more or less protuberant." In the Hydroid Zoophytes, it was observed that the horny skeleton formed, as it were, a case, or external support for the fleshy part of the animal and its polypes, which in the asteroid groups, included in the families of Pennatulidae and Gorgonid, the 'skeleton consists of a central horny or calcareous axis, around which are arranged the polype, bearing fleshy parts. " These horn plants grow with the stem and branches upwards ; the latter are usually situated in a plane and often coalesce. Many earlier and later writers, have believed the stem to be a plant, on which polypes had fixed themselves. In the Gorgonia, a beautiful frame-work of horny matter, consisting of a stem, and a minute net work of branches, occupies the centre of the structure ; and this is clothed with a soft flesh, through which the channels pass that connect the polypes together. This plant is covered with a firm skin, in which a great amount of earthy crystals is deposited, so as to form a crust, and in this, are the hollows or cells by which the polypes are protected. In the dead structures with which we are familiar, under the name of sea fans (Gorgonia flabellum) the dark horny flexible stem, is seen to be covered in many parts with a brittle crust, often brightly colored, which can be scaled off and crumbled to powder. Be tween the two, in the living state, the fleshy coat existed ; the inner part of it, being in contact with the exterior of the horny stem, which was then soft, and scarcely distinct from it, while the exterior part was consolidated by the earthy matter into the firm integument. The animals (in Gorgonia) may be scattered
irregularly over the whole surface, or they may range in series or bands, on opposite sides only, of the stems and branches. The cortex consists of the layer of Polypes, with a variable propor tion of calcareous matter, secreted within their texture ; it is at times, like paper in thinness, and in other species, is thick and spongy." In the Gorgonia verrucosa, Cavolini states that the ova, which are developed in an ovarium, situated at the base of each polype, doubtless in the meso-gastric folds, are discharged by eight small pores, situated at the bases of the eight tentacles. The ova escape as ciliated planulce' (planus flat, applied to flat ciliated forms of larva,) of an ovoid form, which emerge from the ovarian pores with their small end foremost. In the month of June, a Gorgonia, six inches in height, discharged ninety such larva in the space of an hour. They first rose spi rally towards the surface of the water, then swam horizontally. They have the same property as the ciliated planuhe of the marine Hydrozoa, of changing their form, by the contraction of their tissue, a property which the ciliated zoopores of sponges and algae do not possess. When the larva of the Gorgonia rested, they attached themselves to the sides of the vessel, con taining them, by their larger end. The hues of Gorgonidm are gorgeous and varied. The brightest red, crimson, purple, orange, and yellow are common, besides white, brown, and black, and the polypes add other and more delicate tints, when their star-like flowers are in full blossom.