DINOSAURS 179 
must have increased their size and weight. Such a covering 
seems to be clearly indicated by certain grooves and impressions 
that mark their surfaces. (See Fig. 64.) The largest plates are 
Fig. 63.—Limb-bones of Stegosaurus. (After Marsh.) 
1, Fore leg. 2. Hind leg. 
unsymmetrical, and were probably arranged along the back, in 
rows, as In our restoration, Plate XXVI. It will be noticed, by 
those who are familiar with our first edition, that this Plate gives 
