ANNIVERSARY ADDRESS OF THE PRESIDENT. ClX 



consisted of hills and vast, dry, and sandy plains ; some magni- 

 ficent forests of a varied character existed, and the general conditions 

 of soil corresponded in character rather to the snb-tropical regions 

 of Africa and South America, or of Australia, than to the more 

 temperate regions of Europe or South America. 



The great difference between the flora of the Eocene and that 

 of the Miocene epoch is strongly insisted upon, M. De la Harpe 

 stating " that there exists, from the lower Tertiary formations up- 

 wards, a gradual mutation in the vegetation, which tends to ap- 

 proximate it by slow degrees to the existing flora of our own 

 climate ; and yet, that scarcely any one species has passed the 

 boundary of the Eocene to penetrate into the Miocene, and not one 

 of the Miocene plants has been perpetuated into the existing flora." 

 So that, in this respect, remembering that the deduction is appli- 

 cable only to the terrestrial flora, the evidence derived from plants 

 is even more sharp and rigid than that afforded by at least the lower 

 animals. 



The singular character of the Eocene flora, in which are mingled 

 together the plants of various climatal regions, may be appreciated 

 from the following summary of the flora of the Isle of Sheppey : — 



Leguminosse .... 47 species. 



Malvaceae 10 „ 



ProteacecB 2 „ 



Sapindaceae .... 15 „ 



Under this assemblage does not the presence of two species of Pro- 

 teaceae suggest naturally the reflection, that, whilst so early as 

 the Oolitic period, an Australian faima prevailed in the present 

 European region, the appearance of such plants in the Tertiaries may 

 be assumed to indicate, as it were, the gradual retreat of the flora, 

 or, in other words, the shifting of the climatal and other conditions 

 of the earth's surface to the present Australian region? Various figs 

 of large size, a poplar, a maple, three laurels, numerous Leguminosae 

 occur, with some other familiar genera mixed with Proteaceae at 

 Alum Bay ; and M. De la Harpe observes, after reviewing the pecu- 

 liarities of each separate locality, as at Corfe Castle, that it seems 

 impossible to divide the Eocene strata into distinct sections by the 

 flora alone, although the separation between the Eocene and Miocene 

 appears to be marked in the strongest manner. 



The tertiary deposit of the Isle of Mull, described by the Duke of 

 Argyll, is the only one in Great Britain, which, in the author's 

 opinion, can be classed with the Miocene formation, so that he is in 

 accordance with Mr. Prestwich as respects the limits of the Eocene 

 formation in England. The following Table exhibits the result of 

 M. De la Harpe' s inquiries as regards the distribution of the species 

 found in each of the localities which have supplied materials for 

 investigation, the per-centage being attached in each case of com- 

 parison : 



Coniferae .... 

 Nipaceae .... 

 Aurantiaceae 1. 



13 species 

 12 „ 

 . 1 » 



Cucurbitaceae 



..1 » 



