264 THE FOEAMINIFEEA 



conditions of the beds, which comprise a large 

 proportion of glauconitic sandy strata. They bear 

 evidence, however, in the glauconitic granules, or 

 casts, to the former existence of these organisms in 

 prodigious abundance. 



The Neocomian (Urgonian) beds of the Isle of 

 Wight, especially the argillaceous and marly strata 

 known as the Atherfield Clay, contain many minute 

 species of CristeUm-ia and Pulvinulina, which occur 

 in the succeeding beds of the Albian or Gault in 

 other parts in considerable numbers and better 

 developed in point of size. 



The Aptian beds of Surrey, locally known as the 

 Bargate Stone Beds, contain a rich and varied 

 foraminiferal fauna, partly due to the fact that it 

 comprises some species which have been derived 

 from pre-existent strata in the neighbourhood, of 

 Oolitic age. 



At Sandgate the clays of Aptian age also contain 

 many species which bear a strong resemblance to 

 a Lower Gault facies. 



The Aptian beds of Switzerland have also proved 

 to be productive in Foraminifera, and it is in this 

 formation that the Orhitolina lenticularis, previously 

 mentioned, occurs, where it forms a more or less 

 massive rock called the Orhitolina Limestone. 



By far the richest foraminiferal beds of the 

 Lower Cretaceous are those of Albian age, and the 

 Gault clays of England, France, and Germany have 

 furnished several hundred species. Eeuss has very 

 thoroughly described the foraminiferal facies of these 



