Ixviii 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



with the paroxysm. And yet what system of paroxysmal elevations 

 has stood the trying test, when questioned on this principle ? 



It is of the Middle Eocene epoch — that section of the lower ter- 

 tiaries of which the calcaire-grossier of the Paris basin may be cited 

 as a central type and key-stone, — that the Nummulites are especially, 

 and apparently exclusively, characteristic. The supposed carbo- 

 niferous and oolitic Nummulites are of too doubtful a nature to be 

 taken as exceptions. There is, it is true, a Nvimmulite (N. intermedia) 

 found in the Miocene beds of Piedmont, and another {N. yaransensis) 

 in the Lower Miocenes of the Pyrenees. But I am not incUned to 

 conclude with M. d'Archiac that these rare exceptions prove the 

 existence of the last representatives of the genus after the Lower 

 Tertiary fauna had disappeared, but rather to cite them in favour of 

 the view that I have attempted to demonstrate, I trust successfully, 

 when describing during the past year the Lower Tertiaries of the 

 Hampshire basin, — to the eifect that the so-called Lower Miocenes are 

 essentially Lower Tertiaries and a portion of the true Eocene series, 

 and that the passage from them into the Middle Eocenes is perfect 

 and gradual, when we have for our examination an area presenting a 

 full sequence of deposits. 



Nevertheless it is not the less true that the numraulitic horizon 

 is distinctly and definitely marked, and, from the frontiers of China 

 and Thibet, even to the shores of the Atlantic, occupies a fixed 

 position in the geological scale, a place above and succeeding the 

 horizon of the lower tertiary lignites. The full demonstration of 

 this great fact is a precious gain to our science ; and when we consider 

 what a vast area the nummulitic rocks occupy, what mighty moun- 

 tains are made up of them, the prodigious accumulation of indi- 

 viduals of the fossils from which they receive their appellation, and 

 the readiness with which their age can thereby be determined, we 

 cannot but admit that the elucidation of their history has been a boon 

 of no small value to comparative geology. This great tertiary for- 

 mation extends across Europe, Asia, and Africa, forming a zone of 

 98° of longitude, comprised from south to north between the 1 6th 

 and 55th degrees of latitude, and through much of its course exhi- 

 biting a breadth of 1800 miles. In the Himalaya, nummulitic rocks 

 attain an elevation of more than 14,000 feet. 



It will ever be a matter of just pride to our Society, that within 

 our meeting-room and in our proceedings the main task was effected 

 of clearing up the mist that clouded so long the geological history of 

 the great nummulitic formation, and that here it was our indefa- 

 tigable colleague. Sir Roderick Murchison, effected this great advance 

 in tertiary geology. And now that the palaeontology of the Num- 

 mulites has been made as clear as noon-day by the genius and labour 

 of M. d'Archiac, it will ever be a matter of congratulation to us that 

 the cabinets of our Society and the collections of its IMembers were 

 freely and heartily placed at his disposal, and have proved of some 

 value towards enabling him to perfect his researches. 



The discovery, by Sir Charles Lyell and Mr. Dawson, of an am- 



