_Recent Changes in the Continental Areas._--The important fact has been now ascertained, that a considerable portion of the Sahara south of Algeria and Morocco was under water at a very recent epoch. Over much of this area sea-shells, identical with those now living in the Mediterranean, are abundantly scattered, {39}not only in depressions below the level of the sea but up to a height of 900 feet above it. Borings for water made by the French government have shown, that these shells occur twenty feet deep in the sand; and the occurrence of abundance of salt, sometimes even forming considerable hills, is an additional proof of the disappearance of a large body of salt water. The common cockle is one of the most abundant of the shells found; and the Rev. H. B. Tristram discovered a new fish, in a salt lake nearly 300 miles inland, but which has since been found to inhabit the Gulf of Guinea. Connected with this proof of recent elevation in the Sahara, we have most interesting indications of subsidence in the area of the Mediterranean, which were perhaps contemporaneous. Sicily and Malta are connected with Africa by a submerged bank from 300 to 1,200 feet below the surface; while the depth of the Mediterranean, both to the east and west, is enormous, in some parts more than 13,000 feet; and another submerged bank with a depth of 1,000 feet occurs at the straits of Gibraltar. In caves in Sicily, remains of the living African elephant have been found by Baron Anca; and in other caves Dr. Falconer discovered remains of the _Elephas antiquus_ and of two species of _Hippopotamus_. In Malta, three species of elephant have been discovered by Captain Spratt; a large one closely allied to _E. antiquus_ and two smaller ones not exceeding five feet high when adult. These facts clearly indicate, that when North Africa was separated by a broad arm of the sea from the rest of the continent, it was probably connected with Europe; and this explains why zoologists find themselves obliged to place it along with Europe in the same zoological region. Besides this change in the level of the Sahara and the Mediterranean basin, Europe has undergone many fluctuations in its physical geography in very recent times. In Wales, abundance of sea-shells of living species have been found at an elevation of 1,300 feet; and in Sardinia there is proof of an elevation of 300 feet since the human epoch; and these are only samples of many such changes of level. But these changes, though very important locally and as connected with geological problems, need not be further noticed here; as they were not of a {40}nature to affect the larger features of the earth's surface or to determine the boundaries of great zoological regions.