Wonders of Geology. There are few things more curious, strange, and wonderful than the facts revealed by geology. This science is occupied with the structure of the surface of the earth; it tells us of the rocks, gravel, clay, and soil of which it is composed, and how they are arranged. In investigating these materials, the geologists have discovered the bones of strange animals, imbedded either in the rocks or the soil, and the remains of vegetables such as do not now exist. These are called fossil remains; the word _fossil_ meaning _dug up_. This subject has occupied the attention of many very learned men, and they have at last come to the most astonishing results. A gigantic skeleton has been found in the earth near Buenos Ayres, in South America; it is nearly as large as the elephant, its body being nine feet long and seven feet high. Its feet were enormous, being a yard in length, and more than twelve inches wide. They were terminated by gigantic claws; while its huge tail, which probably served as a means of defence, was larger than that of any other beast, living or extinct. This animal has been called the _Megatherium_: _mega_, great, _therion_, wild beast. It was of the sloth species, and seems to have had a very thick skin, like that of the armadillo, set on in plates resembling a coat of armor. There are no such animals in existence now; they belong to a former state of this earth,--to a time before the creation of man. Discoveries have been made of the remains of many other fossil animals belonging to the ancient earth. One of them is called the _Ichthyosaurus_, or fish lizard. It had the teeth of a crocodile, the head of a lizard, and the fins or paddles of a whale. These fins, or paddles were very curious, and consisted of above a hundred small bones, closely united together. This animal used to live principally at the bottoms of rivers, and devour amazing quantities of fish, and other water animals, and sometimes its own species; for an ichthyosaurus has been dug out of the cliffs at Lyme Regis, England, with part of a small one in his stomach. This creature was sometimes thirty or forty feet long. [Illustration: _The jaws of the Ichthyosaurus._] Another of these fossil animals is called the _Plesiosaurus_, a word which means, _like a lizard_. It appears to have formed an intermediate link between the crocodile and the ichthyosaurus. It is remarkable for the great length of its neck, which must have been longer than that of any living animal. In the engraving at the beginning of this number, you will see one of these animals swimming in the water. The following is a view of his skeleton; the creature was about fifteen feet long. [Illustration: _Skeleton of the Plesiosaurus._]