56 



subserved even lo^vlier offices. Betliersden cliurch and the Tvalls 

 surrounding it show vast quantities of the casts of the fresh- 

 water shell Paludina, and the roads are mended with the same 

 stone picked oif the adjacent fields, the fossil casts sometimes 

 being those of another fresh-water mollusc, the Unio Valdensis. 

 The mineral Heavy-spar, or sulphate of barytes, occurs in this 

 clay, some crystals of which I obtained from a septaria which I 

 found at Sandown Bay, in the Isle of Wight. I have also some 

 larger crystals of the same mineral from this formation. (See 

 Annual Report for 1878, -page 28 ) In the succeeding- geological 

 formation the fresh-water fossils of this period give place to 

 those that tell us that a deep sea rolled over the Weald, and the 

 land fossils which it occasionally contains are but the waifs and 

 strays swept out by the rivers to the sea. 



The casts of the fossil shells showing so conspicuously in 

 weathered specimens of the Eethcrsden marble, or sections of them 

 cut through at varying angles in polished slabs, belonging to 

 families of freshwater mollusks, and the rcm-dns of a minute 

 crustacean, the Cypris Yaldensis, modern representatives of which 

 abound in ponds at the present time, and have this year formed 

 objects for microscopical investigation under tbc instruments of the 

 East Kent K"atural History Society, show that the Weald clay is a 

 fresh-water formation. It is stated in Lyell's Elements, page 346, 

 that these minute fossils occur in such abundance in some of the 

 beds that they give them the appearance of micaceous clay. So 

 through all the Wealden, from the Ashburnham beds (in ascend- 

 ing order) to the Weald clay, the fossil remains tell of a fresh- 

 water or estuarine origin. In the calcareous sandstone near 

 Cuckfield, in Tilgate Forest, the first remains were tound of the 

 huge herbivorous reptile called the Iguanodon, so named from the 

 resemblance of the teeth to those of the modern Iguana (pronounced 

 I-gwaw-na), or in India commonly called the Gwana. The 

 modern reptile clips off the herbs on which it feeds without masti- 

 cation, whereas its gigantic fossil forefathers ground down their 

 teeth to slumps in chewing their forage. It has been computed 

 that some of these creatures must have been not less than fifty 

 feet long. The largest thigh bone found measured four feet 

 eight inches in length, and 25 inches round the naiTOwest part. 

 That they were at one time very plentiful may be concluded from 

 Dr. Mantell having personally inspected no less than the remains 

 of seventy-one distinct individuals, These animals, so far as size 

 was concerned, must have been the monarchs of their time, and 

 with their gigantic proportions and thick skins it is unlikely they 

 could have fallen a prey to other creatures, and must have lived 

 out their span of life without either eating or being eaten by the 

 other giants of their day ; nevertheless, in the extremes of youth 

 or old "age, this huge lizard may have fallen a prey to some large 



