determined, but they certainly stand very low in the scale, and have no affinity whatever with the Cephalopods. The subjoined wood-cut represents one of these Shells, so numerous in the Tertiaries that large masses of rock consist of their remains. The Univalve Shells or Gasteropods of the Tertiaries embraced all the families now living, including land and fresh-water Shells as well as the marine representatives of the type. Some of the latter, as, for instance, the Cerithium, are accumulated in vast numbers. The limestone quarries out of which Paris is chiefly built consist wholly of these Shells. The fresh-water basins were filled with Helices, one of which is represented in the following wood-cut, with Planorbis, Limnæus and other Shells resembling those now so common in all our lakes and rivers, and differing from the living ones only by slight specific characters. The Bivalves also have the same resemblance to the present ones, including fresh-water Mussels as well as the marine Clams and Oysters. Among Radiates, the higher Echini (Sea-Urchins) have become numerous, while the other Echinoderms of all families abound. Corals include, for the first time, the more highly organized Madrepores. [Illustration] In the Tertiaries we see the dawn of the present condition of things, not only in the character of the animals and plants, but in the height of the mountains and in the distribution of land and sea. Let us give a glance at the continents whose growth we have been following, and see what these more recent geological epochs have done for their completion. In Europe they have filled the basin in Central France, and converted all that region into dry land: they have filled also the channel between France and Spain; they have united Central Russia with the rest of Europe by the completion of Poland, and have greatly enlarged Austria and Turkey; they have completed the promontories of Italy and Greece, and have converted the inland sea at the foot of the Jura into the plain of Switzerland. But this fruitful period in the progress of the world, when the character of organic life was higher and the physical features of the earth more varied than ever before, was not without its storms and convulsions. The Pyrenees, the Apennines, the Alps, and with them the whole range of the Caucasus and Himalayas, were raised either immediately after the Cretaceous epoch, or in the course of the Tertiaries. Indeed, with this most significant passage in her history, Europe acquired all her essential characters. There remained, it is true, much to be done in what is called by geologists "modern times." The work of the artist is not yet finished when his statue is blocked out and the grand outline of his conception stands complete; and there still remained, after the earth was rescued from the water, after her framework of mountains was erected, after her soil was clothed with field and forest, processes by which her valleys