SEA-SERPENTS 
191 
four and a half feet. This nearly perfect head was for a time a 
stumbling-block to many naturalists, some of whom were of 
Fig. 67. — Skull of Mosasaurus Hoffmanni. The original is 4^ ft. by 2^ ft. 
opinion that it belonged to a whale. Cuvier and others con 
sidered it to be a kind of link between 
the Iguanas and the Monitors.^ 
The entire backbone of the Maestricht 
animal appears to have consisted of one 
hundred and thirty-one vertebrae, of which 
ninety-seven belonged to the tail. The 
total length of the skeleton is estimated at 
twenty-four feet, and the head was about 
one-sixth of the total length. The tail is 
only ten feet long, whereas in a crocodile 
the tail exceeds the length of the body. 
Although in his day the limbs of the 
Mosasaurus were imperfectly known, Cuvier 
1 
Fig. 68. — Teeth of Mo- 
sasaurus (I natural size). 
1«, 2", transverse sections 
of the teeth. 
1 The Monitors are a family of large lizards inhabiting the warmer parts of 
Africa and Asia. They live near the banks of rivers, and some are altogether 
aquatic. They often devour the eggs of crocodiles and aquatic birds. The 
Nile Monitor, or Varanus, grows to a length of six feet. 
