IIS FOOTPRINTS OF A DINOSAUR. 



from the Wealdon with the three toes characteristic of the family. 

 This modification of the hind foot is analogous to the tridactyle 

 hind foot of the rhinoceros and the tapir, and in this respect they 

 are its representative among the huge warm-blooded mammalia of 

 the Tertiary age. Although the Wealden beds of Britain and 

 Germany had yielded a considerable number of Dinosaurian re- 

 mains, the complete osteology of the iguanodon was not established 

 until 1878, when the coal miners of Bernissart, a Belgian village 

 between Mons and Tournay, came upon a deposit containing fossil 

 bones of gigantic reptiles associated with turtle, crocodile, fish, 

 and plant remains. They lay in a depression of the coal-measures, 

 which must have been a lake during the Wealden period. This 

 depression was a mile and a-quarter long, 600 feet broad, and about 

 960 feet deep covered over by cretaceous, tertiary, and quaternary 

 deposits. This Wealden deposit was composed of stratified dark 

 clays intercalated with small fragments of coal and layers of sand, 

 encircled by a wall of detached blocks of carboniferous rocks. The 

 fossil remains are identical with those found in the English and 

 German Wealden beds. It is probable that this remarkable lake 

 was in one of the lateral valleys of the main Hainault valley during 

 the early Cretaceous age, and the river which drained it was one of 

 its tributaries. The dinosaurs and other large animals which 

 frequented its banks would be engulfed in times of floods and 

 some drowned. They have remained undisturbed until their 

 discovery in 1878 by the miners of a Belgian coalpit, when no 

 less than 23 entire skeletons were found, 21 of which belong to 

 a new species, Ir/uanodon Bernissartensis, Boulanger, and two to 

 I. Mantelli, Owen, a smaller and lighter animal which could with 

 greater facility flounder through the swamps and escape the doom 

 of its more ponderous congener. The skeletons were lying on 

 different levels, alternating unfossiliferous beds. In every case, 

 with the exception of a splendid accumulation of bones of the 

 iguanodon found by Dr. Mantell in the Wealden of Tilgate Forest, 

 referred to above, the remains of Wealden dinosaurs have been 

 found as isolated bones, this may be accounted for under the 



