256 [Proc. B. N. F. C, 



plane, the willow, the beech, the alder, the hazel, poplar, elm, 

 pine, the American Liquidambar, sassafras, redwood, and swamp 

 cypress must be Miocene ; and the other that such floras as those 

 of Sheppey and Alum Bay, consisting of palms, Proteaceae, figs, 

 Aralias, aroids, Podocarps, Araucarias, and other tropical and 

 sub-tropical families are alone distinctive of the Eocene. This 

 fundamental error has, owing to the influence of the late Professor 

 Heer, led to the incorporation in the Miocene of all the Tertiary 

 deposits with plants, with insignificant exceptions, of Greece, 

 Italy, Austria, Germany, Switzerland, France, the West of 

 England, Scotland, Ireland, and of all the numerous Tertiary 

 floras round the Arctic Circle, and even of Madeira, Sumatra, 

 and such distant lands. Though the Eocene is in every other 

 respect the more important formation, no floras except such as 

 were actually preserved in situ beneath or between typical 

 Eocene marine formations, have been referred to it. The whole 

 of the American floras with Dicotyledons would also have been 

 absorbed into the Miocene had not stratigraphical evidence 

 come to the rescue. A parcel of plants from Nebraska was sent 

 to Heer to determine, and they were pronounced by him to be 

 Miocene, but since they had been obtained from beneath a 

 massive formation containing Ammonites, Belemnites, and 

 Baculites, with a skeleton of Mososaurus rolled among the leaves, 

 the determination for once was questioned, and, after a long 

 controversy, Heer admitted them to be Cretaceous. Thence- 

 forward he classified such floras containing dicotyledons as he 

 had to describe either as Cretaceous or Miocene, hardly taking 

 into account the Eocene, or the great gap between that and the 

 Chalk. 



The Eocene floras have been discovered of late to be far 

 more varied than had been supposed. Fossil plants are found 

 beneath the mottled plastic clays of Reading. The London 

 clay, with its characteristic sea-shells, actually rests upon them, 

 and they in turn rest upon a bed of sand with layers of oysters, 

 characteristic of the lowest member of our Eocene ; so that 

 there can be no doubt as to the true age of the plants. The 



