268 



THE NATURALIST. 



first member of this series is not found in our own country. The next three 

 formations in descending order may be examined in our own neighbourhood. 

 They may be easily recognised at Keep Hill quarry. There is the soft chalk 

 with flints. These are a distinguishing feature of this formation. Here may 

 be collected Terebratula carnea, T. semiglohata, Ananchytes ovatus, and 

 Mtcraster cor-anguinuin with abundant specimens of a sponge, belonging to 

 the gems Ventriculites. These are characteristic fossils. The soft chalk 

 overlies the chalk rock, in which there ' is an abundance of fossils, but, on 

 account of the exceeding hardness of the formation, it is difficult to extract 

 these treasures uninjured. Below this formation lies the Hard or Lower 

 Chalk. This formation is much more compact than the fia^st ; at places it 

 approaches to the consistency of limestone. The other members of this 

 group are not found in our immediate locality ; but if we journey to Ris- 

 borough, in the escarpment of the hill we shall find every member conform- 

 ably resting on each other, with the exception of the lowest, viz., the Lower 

 Green Sand. The Chalk formation is remarkable for its extent and 

 its composition. The mass of chalk in Europe is immense ; it 

 ranges from the north of Ireland to the Crimea. Its length 

 is nearly ^1200 miles ; its width, from the south of Sweden to the 

 south of Bordeaux is more than 800 miles. In its deepest part, it is not 

 less than a thousand feet in thickness. Whence 'originated this mighty 

 mass % There is little doubt in the minds of scientific observers, that the 

 whole of this large formation has been thrown down in ocean-waters. 

 Probably a very large proportion of it is simple precipitate from water. 

 This, of course, would be a mere granular mass like a mixture of chalk-dust 

 and water. It has been suggested by some judicious observers and accom- 

 plished naturalists that a large proportion of this Chalk formation may have 

 been the calcarious skeletons of Zoophytes, like the corals of our 

 recent oceans. But a very large proportion of some of our chalk 

 hills is an accumulation of microscopic organisms. We know from 

 actual observation that minute but beautiful shells, accumulated by 

 myriads of myriads beyond the power of human intellect to calcu- 

 late, have actually built up the massive layers of the earth's surface. 

 It has been said that we tread upon the ashes of the dead. It is true. But 

 when we walk on yonder hills we tread on the habitations of the dead. 

 Here are palaces of pearly beauty, all thrown together apparently in wild 

 confusion. Ages after ages have rolled over those tenantless abodes, but they 

 are not in ruins. The palaces of earth's mightiest monarchs^have reared 



