NAT. ITIST. DIV. VOL. I.
Remarking on the descriptions of these species, Professor Owen says, "A retrospect of the facts above detailed relative to the Fossil Chelonians of the genus Chelone, or marine family of the order, leads to conclusions of much greater interest than the previous opinions respecting the Chelonites of the London Clay could have suggested. Whilst these fossils were supposed to have belonged to a fresh water genus, the difference between the present fauna and that of the Eocene period, in reference to the Chelonian order, was not very great ; since the Emys, or Cistuda Europera, still abounds on the Continent, after which it was named, and lives long in our own island in suitable localities.
"But the case assumes a very different aspect when we come to the conviction that the majority of the Eocene Chelonites belong to the true marine genus Chelone ; and that the number of species of these extinct Turtles already obtained from so limited a space as the Isle of Sheppey, exceeds that of the species of Chelone now knowh to exist throughout the globe. Notwithstanding the assiduous search of naturalists, and the attraction to the commercial voyager which the shell and the flesh of the Turtles offer, all the tropical seas of the world have hitherto yielded no more than five well-defined species of Chelone ; and of these only two, as the C. 111ydas and C. Caftan°, are known to frequent the same locality. It is obvious, therefore, that the ancient ocean of the Eocene epoch was much less sparingly inhabited by Turtles ; and that these presented a greater variety of specific modifications than are known in the seas of the warmer latitudes of the present day.
" The indications which the English Eocene Turtles, in conjunction with other organic remains from the same formation, afford of the warmer climate of the latitude in which they lived, as compared with that which-prevails there in the present day, accord with those which all the organic remains of the oldest Tertiary deposits have hitherto yielded in reference to this interesting point. • "That abundance of food must have been produced under such influences cannot of course be doubted ; and we may infer that to some of the extinct species, which like the Chelone longiceps and C. planimentum exhibit either a form of head well adapted for pene trating the aoil, or with modifications that indicate an affinity to the Trionyces, was assigned the task of checking the undue increase of the now extinct crocodiles and gavials of the same epoch and locality, by devouring their eggs, or their young becoming probably in return themselves an occasional prey to the older individuals of the same carnivorous Saurian."
Family-Flurialia. Genus-Trionyx.
1. T. Henrici. Eocene at Hordwell.
2. T. Barbs/rm. Eocene at Hordwell.
3. 2'. incrassatua. Eocene Formations of the Isle of Wight.
4. T. marginatus. Eocene Deposit at Hordwell 5. T. rinses. Eocene Beds at Hordwell 6. T. planus. Eocene at Hordwell and Bracklesham.
7. 2'. eireunuralcatus. Eocene at Hordwell.
8. 2'. p ustul at us. Clay at Sheppey.
Family-Paludinosa. Genus-Platemys.
1. P. Bullockii. London Clay.
2. P. Bowerbankii. Clay at Sheppey.
Genus-Emys.
1. E. testudiniformis (Emys de Sheppey, Cuvier?). Eocene Clay of Sheppey.
2. E. lapis. Clay of Sheppey.
3. E. Comptoni.
4. E. bicarinata.
5. E. Delabechii. London Clay, Isle of Sheppey.
Amongst the Fossil remains brought from the Tertiary Formations of India by Dr. Falconer and Major Cautley, are those of a gigantio species of Land-Tortoise. The species referred to has been named Colossochelys Atlas. Portions of its skeleton and a model of the entire animal are now in the collection of the British Museum. • The carapace of this gigantic animal measures in some specimens above 12 feet in length. These remains were found associated with the bones of gigantic extinct Mammalia allied to Pakeotherium, and the other Pachydermata of the Paris basin. In the same deposits Weie also found the remains of several smaller species of Chelonia, and of the one which now inhabits India. There have been also found in the same locality the remains of 'gigantic crocodiles, differing fiona those now inhabiting India, and several species of elephant.
In the 'Reports' of the United States Surveying Expedition in Wisconsin, Iowa, and Minesota, in 1850, an account is •giyen of the discovery of the remains of a large number of species of Ohx7onie, both Tortoises and Turtles, with the remains of extinct forms of Mommalia in the district of the Mauvaises Terres on the Missouri.