﻿188 Correspondence — Dr. OttoMr Feistmantel. 



during the deposit of our Eocene series differed widely at eacli period. 

 IS^ow my acquaintance with the Eocene formation, and with its 

 Pauna in various ways/ is somewhat more than Mr. Gardner gives me 

 credit for; and I distinctly traverse his suggestion that the Pauna 

 of the beds he names aifords (when allowance is made for varying 

 conditions of bottom and depth, and for the difficulty in making 

 comparisons between faunas of which some are marine, some fluvio- 

 marine, and some fluviatile, as is the case with these beds) any indica- 

 tion whatever of a diversity of climate. Fortifying the opinion which 

 I have formed from my own acquaintance with these beds, and with 

 their Fauna, by that to the same purport of my father, who has made 

 the study of the Tertiary Mollusca the occupation of the greater part 

 of a long life, I contend that, so far as the past can be judged from 

 what is known of the present, this fauna is of tropical character 

 throughout. It was once thought that the mollusca of the Thanet 

 sands indicated a colder climate than did those of the beds which 

 succeed it, but the subsequent discovery of a Nautilus in these sands has 

 made even that view difficult to be maintained. Moreover, not only do 

 the Eocene beds of Western Europe present this character, but the 

 close similarity between Eocene mollusca found in the Aral-sea region 

 and those from the English and French beds indicates that this climate 

 prevailed under nearly the same latitude as far, at least, as the 

 meridian of 60° East longitude. 



I have trespassed thus much on your space, to vindicate the opposi- 

 tion which 1 offered to Mr. Gardner's hypothesis of oscillations of 

 climate during the Eocene period; and I could pursue the subject 

 further, as well as offer reasons for disagreeing from his alternative 

 theory of the existence of a mean annual temperature, which permitted 

 the growth of sub-tropical and more temperate forms side by side ; but 

 as he expresses his intention of not entering into any discussion with 

 me, this would be undesirable, as I should be sorry to tempt him into 

 any descent from the serene elevation on which he has placed himself. 



I would, however, observe that, although the explanation which I 

 offered as to the Hampshire Flora seemed to me the most obvious in that 

 particular case, and although I do look upon both of Mr. Gardner's 

 hypotheses as remote from the truth, I have nothing to say in opposition 

 to Prof. Heer's view that difference of climate according to latitude did 

 not, so far as it is evidenced by fossil vegetation, begin to show itself 

 until late in the Mesozoic division of the Earth's history. 



Seakles V. "Wood, Jun. 



THE GONDWANA SERIES OF INDIA.^ 

 SiE, — I have some remarks and corrigenda "to add to my article on 



the Gondwana Series of India.^ 



First, as regards the classification of the whole area, as used in the 



above-mentioned paper, I have to state that it should be, properly, as 



follows : 



1 Amongst them, the original and first disinterment from the Hampshire cliff, in 

 association with my father (now thirty-four years ago), of the remains of "Alligator, 

 Turtle, and other R-eptiles," to which Mr. Gardner in his paper refers. 



2 The publication of this letter has been by an unfortunate oversight delayed a 

 month. — Edit. Geol. Mag. 



3 See Geol. Mag. Dec. II. Vol. III. p. 481. 



