Sir James Ross, in his Antarctic expedition, brought up corals from a great depth with the lead; and these he remitted for accurate examination to Mr. Stokes and Professor Forbes. Westward of Victoria Land, in the neighbourhood of the Coulman Island, in 72° 31′ south lat., and at a depth of 270 fathoms, Retepora cellulosa, a Hornera, and Prymnoa Rossii. (the latter very similar to a species common to the coasts of Norway,) were found alive and in a perfectly fresh condition.[LH] In the far north too, the Greenland _Umbellaria Grœnlandica_ has been brought up alive by whale fishers from a depth of 236 fathoms.[LI] The same relation between species and locality is met with among sponges, which however are now regarded as belonging more to plants than to zoophytes. On the shores of Asia Minor, the common marine sponge is brought up from depths varying from 5 to 36 fathoms, although one very small species of the same genus is only found at a depth of at least 180 fathoms.[LJ] It is difficult to divine what hinders the Astræas, Madrepores, Mæandrinas, and the whole group of tropical phyto-corals, which are capable of constructing large cellular calcareous walls, from living in very deep strata of water. The decrease of temperature is very gradual, the diminution of light nearly the same, and the existence of numerous Infusoria at great depths of the Ocean proves that there cannot here be any deficiency of food for polyps. In opposition to the hitherto generally adopted opinion respecting the absence of all organisms and living creatures in the Dead Sea, it is worthy of notice that my friend and fellow-labourer, M. Valenciennes, has received, through the Marquis Charles de l’Escalopier, and through the French Consul Botta, beautiful specimens of Porites elongata from the Dead Sea. This fact is the more interesting, because this species is not found in the Mediterranean, but only in the Red Sea, which, according to Valenciennes, has but few organisms in common with the Mediterranean. As a sea-fish, a species of Pleuronectes, advances far into the interior of France, and accustoms itself to gill-respiration in fresh water, so also does a remarkable flexibility of organization exist in the above-mentioned coral-animal (Porites elongata of Lamarck), as the same species lives both in the Dead Sea, which is supersaturated with salt, and in the open ocean near the Séchelles Islands.[LK]