President of the Geological Society for 1850. 7 



139 species of echinoderms described by him from the num- 

 mulitic beds of the Mediterranean, one species only is com- 

 mon to them and the calcaire grossier. The same geologist 

 maintains that all the fish of Glarus and Monte Bolca, which 

 according to the latest opinions must be classed as eocene, 

 differ entirely from those of Sheppy.* Yet I am by no 

 means disposed to question, on the ground of this want of 

 agreement in the ichthyolites, that the Glarus slates are in 

 truth tertiary, still less to doubt that the limestone of Monte 

 Bolca belongs to the same period : ^I have always regarded 

 the latter as eocene from the time when I visited that locality 

 in company with Sir Roderick Murchison in 1828. You have 

 seen also, in the classification of the three successive eocene 

 formations established by Mr Prestwich for the older tertiary 

 deposits of Great Britain, that while each division is charac- 

 terized by its peculiar assemblage of shells, a part only of 

 the species pass from one division to another, and that the 

 specific difi^erence of the mammalia belonging to each divi- 

 sion, and still more of the first, as determined by Agassiz, is 

 extremely marked. 



The researches above alluded to, of Sir Roderick Murchi- 

 son in the Alps in 1847, and the palseontological evidence of 

 various eminent writers brought together by him in illustra- 

 tion of his views, have, I think, shown unequivocally, that, 

 together with the nummulitic limestone, an enormous thick- 

 ness of overlying strata of dark-coloured slates, marls, and 

 fucoidal sandstones, provincially called Flysch, are separable 

 from the cretaceous system of Northern Europe, and must 

 also be regarded as lower eocene. His attempt however to 

 make out a passage from the tertiary to the secondary series 

 by means of an intervening group of marls, green sandstone, 

 and impure limestone, appears to me to be far less success- 

 ful, since a true representative of the Maestricht beds is 

 wanting in the Alps, or is very ill-defined, and no other equi- 

 valent assemblage of organic remains is enumerated suffi- 

 ciently rich in forms, or intermediate in character, to fill up 

 the wide gap between the eocene strata and the chalk. 



* Bulletin, vol. v. pp. 414, 415. 



