From this formation on the shores of Whitecliff Bay, Dr. Mantell obtained a fine specimen of a fan palm, Flabellaria Lamanonis, Brong., a plant first obtained from beds of corresponding age in the suburbs of Paris. The well-known building-stone of Binstead, near Ryde, a limestone with numerous hollows caused by Cyrenæ which have disappeared and left the moulds of their shells, belongs to this subdivision of the Bembridge series. In the same Binstead stone Mr. Pratt and the Reverend Darwin Fox first discovered the remains of mammalia characteristic of the gypseous series of Paris, as Palæotherium magnum (Fig. 174), P. medium, P. minus, P. minimum, P. curtum, P. crassum; also Anoplotherium commune (Fig. 173), A. secundarium, Dichobune cervinum, and Chæropotamus Cuvieri. The Palæothere above alluded to resembled the living tapir in the form of the head, and in having a short proboscis, but its molar teeth were more like those of the rhinoceros. Palæotherium magnum was of the size of a horse, three or four feet high. The woodcut, Fig. 174, is one of the restorations which Cuvier attempted of the outline of the living animal, derived from the study of the entire skeleton. As the vertical range of particular species of quadrupeds, so far as our knowledge extends, is far more limited than that of the testacea, the occurrence of so many species at Binstead, agreeing with fossils of the Paris gypsum, strengthens the evidence derived from shells and plants of the synchronism of the two formations.

Osborne or St. Helen’s Series, A.2.—This group is of fresh and brackish-water origin, and very variable in mineral character and thickness. Near Ryde, it supplies a freestone much used for building, and called by Professor Forbes the Nettlestone grit. In one part ripple-marked flagstones occur, and rocks with fucoidal markings. The Osborne beds are distinguished by peculiar species of Paludina, Melania, and Melanopsis, as also of Cypris and the seeds of Chara.

Headon Series A.3.—These beds are seen both in Whitecliff Bay, Headon Hill, and Alum Bay, or at the east and west extremities of the Isle of Wight. The upper and lower portions are fresh-water, and the middle of mixed origin, sometimes brackish and marine. Everywhere Planorbis euomphalus, Fig. 175, characterises the fresh-water deposits, just as the allied form, P. discus, [Fig. 170,] does the Bembridge limestone. The brackish-water beds contain Potamomya plana, Cerithium mutabile, and Potamides cinctus ([Fig. 37]), and the marine beds Venus (or Cytherea) incrassata, a species common to the Limburg beds and Grès de Fontainebleau, or the Lower Miocene series. The prevalence of salt-water remains is most conspicuous in some of the central parts of the formation.

Among the shells which are widely distributed through the Headon series are Neritina concava (Fig. 177), Lymnea caudata (Fig. 178), and Cerithium concavum (Fig. 179). Helix labyrinthica, Say (Fig. 176), a land-shell now inhabiting the United States, was discovered in this series by Mr. Searles Wood in Hordwell Cliff. It is also met with in Headon Hill, in the same beds. At Sconce, in the Isle of Wight, it occurs in the Bembridge series, and affords a rare example of an Eocene fossil of a species still living, though, as usual in such cases, having no local connection with the actual geographical range of the species. The lower and middle portion of the Headon series is also met with in Hordwell Cliff (or Hordle, as it is often spelt), near Lymington, Hants. Among the shells which abound in this cliff are Paludina lenta and various species of Lymnea, Planorbis, Melania, Cyclas, Unio, Potamomya, Dreissena, etc.

Among the chelonians we find a species of Emys, and no less than six species of Trionyx; among the saurians an alligator and a crocodile; among the ophidians two species of land-snakes (Paleryx, Owen); and among the fish Sir P. Egerton and Mr. Wood have found the jaws, teeth, and hard shining scales of the genus Lepidosteus, or bony pike of the American rivers. This same genus of fresh-water ganoids has also been met with in the Hempstead beds in the Isle of Wight. The bones of several birds have been obtained from Hordwell, and the remains of quadrupeds of the genera Palæotherium (P. minus), Anoplotherium, Anthracotherium, Dichodon, Dichobune, Spalacodon, and Hyænodon. The latter offers, I believe, the oldest known example of a true carnivorous animal in the series of British fossils, although I attach very little theoretical importance to the fact, because herbivorous species are those most easily met with in a fossil state in all save cavern deposits. In another point of view, however, this fauna deserves notice. Its geological position is considerably lower than that of the Bembridge or Montmartre beds, from which it differs almost as much in species as it does from the still more ancient fauna of the Lower Eocene beds to be mentioned in the sequel. It therefore teaches us what a grand succession of distinct assemblages of mammalia flourished on the earth during the Eocene period.