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line I am now attempting, to describe the successive groups above 

 the chalk in terms the most general, and in divisions the most com- 

 prehensive; especially, as they appear in connexion with our labours 

 of the past year. 



I must, however, notice one more group in the succession of 

 marine deposits, before I can complete the ascending series and 

 reach the limits of history : the name tertiary cannot perhaps with 

 propriety be applied to it, as the animal remains contained in it 

 are almost exclusively of the species now living in the nearest seas. 

 To this class we may refer certain shelly deposits in the West India 

 Islands — on the shores of the Red Sea — and on various parts of 

 the shores of Italy, Sicily, and Spain. Their position, as might be 

 expected, is generally low. But near the focus of volcanic action 

 they rise to more considerable elevations : in proof of which 1 need 

 only state, that beds of shells are found on the mountains of Sicily 

 three thousand feet above the level of the Mediterranean, and of 

 the same species with those now living in its waters *. 



Such are the steps by which we ascend through the divisions of 

 the tertiary period. I need not, however, inform you that we can 

 seldom determine their relations by the mere evidence of super- 

 position. Most frequently they appear in detached masses, the age 

 of which can only be known by their fossils. This kind of evidence 

 is, however, sometimes brought before us in a manner at once the 

 most complicated and the most conclusive. It is to the labours 

 of MM. Deshayes, Basterot, and other expert naturalists, who are 

 devoting their talents and time to the completion of great works on 

 the organic forms of the several tertiary groups, that we must 

 look for information, which in the end may give us the means of a 

 safer and wider induction. 



With the exception of an interesting notice by Dr. Buckland of 

 the occurrence of agates in the dolomitic strata of the Mendip 

 Hills, not a single memoir has been read before us during last year, 

 on the mineralogical structure of any part of the British Isles. I do 

 not mention this without regret ; for while any part of the struc- 

 ture of this country is unexplored, we have left unfinished that 

 task, to perform which was the first great object of our association. 

 The work of Mr. Phillips on the strata and organic remains of the 

 Yorkshire coast offers, however, a splendid contrast to this portion 

 of our year's productions. The clearness of the descriptions, the 

 accuracy of the sections, the figures of more than 400 fossils faith- 

 fully arranged according to their grouping in the formations be- 

 tween the new red sandstone and the chalk, combine to make it 

 one of the most valuable and instructive Essays in our language. 



Much, Gentlemen, remains to be done, before the structure of the 

 various formations of the British Isles can safely be appealed to 



* This important fact was communicated by Mr. Lvell, and is described 

 by him in a work now in the press. 



