impeded its progress through the water ; presenting a striking contrast to the organization which so admirably fits the ichthyosaurus to cut through the waves. May it not therefore be concluded (since, in addition to these circumstances, its respiration must have required frequent access of air) that it swam upon or near the surface, arching back its long neck like the swan, and occasionally darling it down at the fish which happened to float within its reach ?
It may perhaps have lurked in shoal water along the coast, concealed among the sea-weed, and raising its nostrils to a level with the surface from a considerable depth, may have found a secure retreat from the assaults of dangerous enemies ; while the length and flexibility of its neck may have compensated for the want of strength in its jaws and its incapacity for swift motion through the water, by the suddenness and agility of the attack which they enabled it to make on every animal fitted for its prey, which came within its extensive sweep.
The name I have originally given to this animal, Plesiosaurus, (approximate to the Saurians,) may appear rather vague in this stage of our knowledge, and an appellation derived from its peculiar length of neck might be preferred : but for the present I shall retain the old generic name, adding for specific distinction the well-known Homeric epithet Dolichodeirus, as characterizing the most striking peculiarity of its osteology. I am the rather induced to follow this course, because I think it very probable, from specimens which I have examined, that species of Plesiosaurus with shorter necks exist in other strata. I have already figured a column, belonging to an animal of this genus, in which the proportions of the Plesiosaurus Dolichodeirus are inverted, the vertebrae of the neck being considerably thinner than those of the body. Professor Buckland has since obtained from Market Raisin large fragments of the skeleton of the species to which that vertebral column must have belonged : its remains are common in the Kimmeridge or Oaktree clay. From its enormous size I shall provisionally indicate this species as Plesiosaurus giganteus, and I hope hereafter (in union with my friend) to submit drawings and a description of those remains to the Society.
With reference to the elucidation of all these questions, I cannot but congratulate the scientific public that the discovery of this animal has been made at the very moment when the illustrious Cuvier is engaged in, and on the eve of publishing, his researches on the fossil ovipara : from him the subject will derive all that lucid order which he never has yet failed to introduce into the most obscure and intricate departments of comparative anatomy