INTRODUCTORY. 7 
Chelonians, or Tortoises, 468 Saurians, or Lizards, 586 Ophidians, 
or Snakes, and 218 Batrachians. This will give one some idea of 
the great variety of these creatures. Since 1854, however, a 
period of forty years, a great addition has been made to our 
knowledge of these animals. For example, it may be mentioned 
that something like 1700 different kinds of Lizards, 1800 different 
kinds of Snakes and 300 different kinds of Tortoises are now known | 
to science; and, perhaps, our knowledge of the Batrachians has 
increased with quite as great strides. 
