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4 BRITISH EOCENE ELORA. 



others common to Greenland. The newly-discovered deposit at Canna appears to have 

 yielded only two species, both of which are also found at Mull. The Irish beds are generally 

 admitted to be of the same age as those of Scotland, and have many species in common. 

 They are especially interesting ; for, while containing several species characteristic of our 

 Middle and Lower Eocene, they also contain, like some of the Lower Eocene beds in 

 Erance, Greenland species not yet recognised at Mull, As connecting links all these are 

 therefore of the highest importance. 



It is scarcely less important to obtain collections of plant remains from a series of beds 

 of well-defined ages from as nearly the same latitude and longitude as possible, for a 

 scale of temperatures, ranging from at least the Lower Eocene to the Pliocene, could be com- 

 piled from them. In England we have a probably unrivalled series of Eocene plants, whose 

 relative ages, with the exception of those from Bovey-Tracy, are established on the most 

 unequivocal palseontological and stratigraphical evidence. For the Lower Eocene group 

 these are the floras from Newhaven, Reading, Dulwich, Bromley, Croydon, Lewisham, 

 &c. ; for the London Clay group, Sheppey, Heme Bay, Alum Bay, and Studland ; for the 

 Middle Eocene, Bournemouth and Bovey-Tracy ; and for the Upper Eocene and Oligo- 

 cene, Hordwell, Gurnett Bay, and Hempstead. Erom most of these localities collections 

 may still be made, and some of them are remarkably prolific. Bournemouth has yielded 

 a far larger number of distinct species of a Tertiary flora than any other locality ; and I 

 have received during the past two years nearly 20,000 fruits from Sheppey and Heme 

 Bay. 



In Erance the series of plant-bearing beds is even more complete. It commences, 

 it is believed, at a lower stage, that called the " Paleocene " by Schimper, and extends 

 upwards to the Upper Pliocene. The following list of localities from which floras have 

 been obtained has been supplied by the Marquis de Saporta, who has at all times 

 rendered me Avilling assistance. The Paleocene plants may to some extent, however, be 

 equivalent to the Lower Eocenes of England. They are represented in the Paris Basin 

 by the tuffs of Sezanne and the Gres de Belleu or Gres du Soissonnais, in Belgium by 

 the Gelinden limestone, and by the concretionary limestone of St. Gely (Herault) in 

 the South. The Calcaire-grossier stage is represented in the Paris Basin at the Trocadero 

 and by the Gres de Brives, and the Gres de Marne-et-Loire and of the Sarthe. It is, 

 however, in Languedoc and Provence that the floras become of greatest interest, for there 

 the sequence is uninterrupted from the Eocene, through the Tongrian or Oligocene, to 

 the Mayencian stage of Heer. The exact sequence is : 



Upper Eocene : Zone of Palaeotherium. — Gypsum of Aix. 



Lower Oligocene. — Gypsum of Garges. 



Middle Oligocene. — Calcaire marneux of St. Zacharie. 



Middle Oligocene. — Calcaire marneux littoraux of the Marseilles Basin. 



Upper Ohgocene. — Bonnieux and Cereste near Apt. 



