166 EXTINCT MONSTERS 
remains of Iguanodon at South Kensington, and also some of the 
gigantic tracks already alluded to. A complete cast of a skeleton 
may be seen in the reptile gallery of the Natural History 
Museum. 
The Bernissart specimens even afford some evidence as to the 
nature of the integument, or skin, and this supports the idea 
previously held that the creature possessed a smooth skin, or, 
at least, only slightly roughened. The muzzle was quite tooth- 
less, and perhaps may have been sheathed in horn, like the beak 
Fig. 56.—Tracks of Igwanodon, much reduced. From Wealden strata, Sussex. 
of turtles—an arrangement highly useful for biting off the leaves 
of trees, 
Probably it passed much of its time in the water, using its 
immense powerful tail as an organ of propulsion. When swim- 
ming slowly it may have used both sets of limbs, but when going 
fast it probably fixed its fore limbs closely beside its body, and 
drove itself through the water by means of the long hind limbs 
alone. M. Dollo, of Brussels, is preparing a final monograph 
on the Bernissart Iguanodons, a work to which paleontologists 
