which are now dispersed through various classes and orders of existing animals, but are no longer united in the same genus. Thus, in the same individual, the snout of a Porpoise is combined with the teeth of a Crocodile, the head of a Lizard with the Vertebræ of a fish, and the sternum of an Ornithorhynchus with the paddles of a Whale. The general outline of an Ichthyosaurus must have most nearly resembled the modern Porpoise, and Grampus. It had four broad feet, or paddles, (Pl. 7,) and terminated behind in a long and powerful tail. Some of the largest of these reptiles must have exceeded thirty feet in length.
There are seven or eight known species of the genus Ichthyosaurus, all agreeing with one another in the general principles of their construction, and the possession of those peculiar organs, in which I shall endeavour to point out the presence of mechanism and contrivance, adapted to their habits and state of life. As it will be foreign to our purpose to enter on details respecting species, I shall content myself with referring to the figures of the four most common forms (Plates 7, 8, 9.)[1]
- ↑ Pl. 7, is a large and nearly perfect specimen of the Ichthyosaurus Platyodon, from the lias at Lyme Regis, being one of the splendid series of Saurians, Purchased in 1834 of Mr. Hawkins by the British Museum. Portions of the paddles, and many lost fragments, are restored from the corresponding parts which are preserved; a few vertebræ, and the extremity of the tail are also restored conjecturally. Beautiful and accurate lithographed figures of this specimen, and of the greater part of this collection, are published in Mr. Hawkins's Memoirs of Ichthyosauri and Plesiosauri, London, 1834. Pl. 8. Fig. 1, is a small specimen of the Ichthyosaurus Communis, from the lias at Lyme-Regis, belonging to the Geoll Soc. of London. Pl. 8, Fig. 2, a small Ichthyosaurus Intermedius, from the lias at Lyme Regis belonging to Sir Astley Cooper. Pl. 9, Fig. 1, an Ichthyosaurus Tenuirostris, from the lias of Street, near Glastonbury, in the collection of Rev. D. Williams. Fig. 2 is the continuation of the tail, and Fig. 3, the reverse of the head. The teeth in this species are small, and in due proportion to the slender character of the snout.
