THE TERTIARY ERA 61 



cemented by iron oxide. In Whitecliff Bay the Brackles- 

 ham Beds (585 ft.) consist of clays, sands, and sandy 

 clays, mostly dark, greenish and blue in colour, containing 

 marine fossils and lignite. Sir Richard Worsley, in his 

 History of the Isle of Wight, tells that in February, 1773, 

 a bed of coal was laid bare in Whitecliff Bay, causing 

 great excitement in the neighbourhood. People flocked 

 to the shore for coal, but it proved worthless as fuel. It 

 has, however, been worked to some extent in later years. 

 In some of the beds are many fossils. Numbers have 

 lately been visible where a large founder has taken place. 

 There are large shells of Cardita planicosta and Tunitella 

 imbricataria. They are, however, very fragile. In a 

 stratum just above these are numbers of a large Nummu- 

 lite (Nummulites Icsvigatus). These are round flat shells 

 like coins, hence the name (Lat. nummus, a coin). They 

 are a large species of foraminifera. We may split them 

 with a penknife ; and then we see a pretty spiral of tiny 

 chambers. A smaller variety, 2V. variolarim, occurs a 

 little further on, and a tiny kind, N. elegans, in the 

 Barton clay. One of the most striking features of 

 the later Eocene is the immense development of 

 Nummulite limestones vast beds built up of the 

 delicate chambered shells of Nummulites, which extend 

 from the Alps and Carpathians into Thibet, and from 

 Morocco, Algeria, and Egypt, through Afghanistan and 

 the Himalaya to China. The pyramids of Egypt are 

 built of this limestone. 



The Bracklesham beds are followed by the Barton clay, 

 famous for the number of beautiful fossil shells found 

 at Barton on the Hampshire coast. At Whitecliff Bay 

 the fossils are, unfortunately, very friable. At Alum 

 Bay the pathway to the shore is in a gully in the upper 

 part of the Barton clay. The strata consist of clays, 

 sands, and sandy clays. The base of the beds is marked 

 by the zone of Nummulites elegans. Numerous very 



