Page:Geology and Mineralogy considered with reference to Natural Theology, 1837, volume 1.djvu/137

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at the head of the surprising discoveries, which have been made relating to the family of Saurians, we may rank the remains of many extraordinary species, which inhabited the sea; and which present almost incredible combinations of form, and structure; adapting them for modes of life that do not occur among living reptiles. These remains are most abundant throughout the lias and oolite formations of the secondary series. In these deposites we find not only animals allied to Crocodiles, and nearly approaching to the Gavial of the Ganges; but also still more numerous gigantic Lizards, that inhabited the then existing seas and estuaries.

Some of the most remarkable of these reptiles have been arranged under the genus Ichthyosaurus, (or Fish Lizard,) in consequence of the partial resemblance of their vertebræ to those of fishes. (See Plate 1, Fig. 51, and Plates 7, 8, 9.) If we examine these creatures with a view to their capabilities of locomotion, and the means of offence and defence which their extraordinary structure afforded to them; we shall find combinations of form and mechanical contrivances