The family, as we have already said, take their names from their supposed resemblance to the Mushroom. "But," says Peyssonnel, "there is this difference between terrestrial and marine mushrooms--that the former have leaflets below, and those of the ocean have them above (Fig. 72). These leaflets are only expansions of the Madrepores. Now, although I have not actually examined these petrified Mushrooms of the sea, I have no reason to doubt but that they are true genera or species of Madrepores, containing, like others, the zoophytes which form them. In my travels in Egypt, in 1714 and 1715, I never heard it said that the Nile could produce them." In this last remark, Peyssonnel makes allusion to the opinion entertained by many ancient authors, that the Fungia were productions of the Nile. The animal is gelatinous or membranous, generally simple, depressed, and oval, with mouth superior and transverse, in a large disk, which is covered by many thick cirrhiform tentacula; the polypidom is rendered solid internally by a calcareous solid deposit of a simple figure, having a star of radiating, acutely-pointed lamellæ above, and simple rays, full of wrinkles, beneath. There are nine species, mostly natives of the Indian Seas, which De Blainville arranges in three groups, according as they are simple and circular, simple and compressed, or complex and oblong. In _Fungia echinata_, represented in Fig. 72, we have a species which inhabits the Indian and Chinese Seas. It belongs to the last group, being oblong in form, convex above, and concave below. The hollow, from which the lamellæ or chamber-walls proceed, are of considerable length; the toothed partitions are very irregular, thin and prickly, resting upon their lower edge, in order to leave the concave portion of the field free to a host of excrescences, resembling the roof of a grotto studded with small stalactites. [Illustration: Fig. 73. Fungia agariciformis (Lamarck).] The conformation of the softer parts of this polypus has been described by many travellers. The upper portion of the body of the animal, corresponding to the lamelliform part of the polypus, is furnished with scattered tentacula, very long in some species, and remarkably short in others. These tentacula appear to terminate in a small sucker, and the animal seems to recover its position with difficulty, when overturned. In order to complete our description of these curious madrepores, we may refer to _Fungia agariciformis_, represented in Fig. 73. This remarkable species inhabits the Red Sea and the Indian Ocean, and is here represented with its polyps. * * * * *