XXXVI. 



his three divisions of the Isle of Wight beds into the Lower Freshwater formation, the 

 Middle Marine formation, and Upper Freshwater formation. This classification held its 

 ground for sometime, until it was materially rectified by Professor Prestwich, so thoroughly 

 did he grasp the history of the Tertiary period from the time the Thanet beds began to 

 cover the denuded chalk to the dawn of the Pliocene period, when the fauna and flora of 

 England assumed their present aspect. The Professor divided the Hampshire Tertiaries 

 into three groups : the first and lowest group he assigned to the Woolwich and Reading 

 beds and London clay ; the second to the Bagshot and Bracklesham beds, which he 

 synchronizes with the lower part of the calcaire grossiere of the Paris basin. To the 

 third group, which lies outside our boundary, consisting of green marls, limestones, and 

 siliceous sands of freshwater and marine origin, he assigns all the beds upwards from the 

 Headon and Brockenhurst beds to the uppermost Hempstead marine beds, which had 

 been overlooked by Webster. Mr. Starkie Gardner, whose labours have been so 

 eminently successful in developing the British Tertiary flora, has amassed from the 

 fertile leaf -beds of Bournemouth unerring evidence of the climatal changes to which the 

 Hampshire basin has been subject. To my personal intercourse with Mr. Gardner, and 

 access to his works and memoirs, I am the better enabled to offer you the following 

 notes : The Thanet beds, which are the lowest of the series, are absent from this southern 

 edge of the Hampshire basin. The Woolwich and Reading beds, the next in succession, 

 comprising mottled clays, intercalated sands, and occasional beds of rolled black flint 

 pebbles, occupy a very subordinate place. Their development, which is very insignificant 

 here, has a large extension westward in the neighbourhood of Bloxworth, Coombe 

 Keynes. and Lulworth. Beds of similar pebbles occur at Chalbury and Edmondsham 

 in connection with Ostrea Bellovacina, which Mr. Gardner considers mark the 

 western shore of the London clay beds, as they become more distinctly fluviatile 

 from east to west. He distinguishes a difference between the floras of the Woolwich 

 and Reading beds, the latter marking a more temperate period and identical with 

 the Tertiary deposits of Switzerland and Greenland. Anomia sub-cretacea occurs 

 equally at Reading and Bournemouth ; Lygodium Kaulfaussi in the Woolwich beds, 

 at Croydon and Counter Hill, as well as in the beds at the western extremity of 

 the Bournemouth Cliffs. Near Poole Harbour both Anomia and Lygodium are 

 associated with Taxodium Europseum, strengthening the view that plants hitherto 

 claimed to be typical of the Miocene age lived in England before the palm and 

 other tropical ptants of the London clays had been introduced at Studland and 

 Corfe. The flora of the Woolwich and Reading age have quite a temperate aspect. 

 The leaves of the plane tree and many other dicotyledons prevail, similar to many 

 Greenland tertiary forms, and showing a remarkable relationship. It is probable as the 

 temperature increased during the deposition of the London clays the flora of the three 

 great continents moved northward as far as Greenland and became mixed up together. 

 A migration of types, now growing in Australia, took place in Europe, succeeded by 

 another, which is now represented in Central America. At this period the large Bulimus 

 lived, which gives the name to a bed of limestone at Bembridge, in the Isle of Wight, 

 belonging to a group, the type which is now represented in the West Indies. The 

 tropical flora arriving from America was arrested by the severance of the western 

 communication and an extension of the eastern communication, which accounts for these 

 tropical forms in France, Germany, and Greece, and the absence of the previous 

 American types in those regions. The presence of Australian and American forms is a 

 study of much interest. The former, which had a sudden and great extension, preceded 

 the latter. The Studland and Corfe flora are good examples of the Australian type of an 



