528 HISTORY OF GEOLOGY AND PALEONTOLOGY. 



related to Upper Cretaceous faunas in other French localities. 

 They pointed out that the upheaval of the Pyrenees had taken 

 place after the accumulation of these intermediate deposits, and 

 therefore proposed to include them with the Cretaceous system. 

 It was admitted, however, that the Nummulite rocks of Ronca, 

 Monte Bolca, and a few other localities were, as Elie de Beau- 

 mont had said, of Tertiary age. 



The Swiss geologists, Studer and Escher von der Linth, 

 regarded the Nummulite deposits of Southern Europe as passage- 

 beds between the Mesozoic and Cainozoic periods, the affinity 

 being greater with the Cretaceous than with the Eocene 

 faunas. Leymerie (1843) treated the Nummulite deposits in 

 the Pyrenees as an independent formation (Terrain epicretace) 

 between Cretaceous and Tertiary, and Tallavignes sub-divided 

 this formation into two horizons, Iberien and Alaricien. 



Deshayes and Raulin contested the supposed close affinity 

 of the Nummulite group with 'the Cretaceous series, and em- 

 phasised the decided Eocene character of the Nummulite fauna. 

 D'Archiac gave an exhaustive account of the Nummulite forma- 

 tion in his Histoire des Progres de la Geologic, and brought 

 forward an imposing array of arguments in favour of the 

 Tertiary age of these deposits. Three years afterwards, in 

 1853, a handsomely illustrated monograph was issued under the 

 conjoint authorship of D'Archiac and Haime. It contained a 

 complete synopsis and description of all Nummulite species, 

 and demonstrated that the genus Nummulites was not known 

 to occur either in the Cretaceous deposits or in the younger 

 Tertiary groups. This work was regarded as practically decisive, 

 and the Nummulite formations were assigned to the Eocene 

 period. 



Meantime the Tertiary deposits of Central and Northern 

 Europe were made the subject of many special researches. 

 The memoirs by Galeotti (1837) and by A. Dumont (1836-41) 

 on the Belgian development were far-reaching in their influence. 

 Dumont distinguished (1849-52) a series of palaeontological 

 zones, and named the Belgian sub-divisions accordingly as Heer- 

 sien, Landenien, Ypresien, Paniselien, Bruxellien, Laekenien, 

 Tongrien, Rupelien, Bolderien, Diestien, Scaldisien. Sir Charles 

 Lyell afterwards showed that the first six of Dumont's "Stages" 

 correspond to the Lower and Middle Eocene ; Tongrien and 

 Rupelien represent Upper Eocene ; Bolderien represents the 

 Miocene; and Diestien and Scaldisien are, the equivalents 



