THE ROYAL NATURAL HISTORY. 
REPTILES. 
CHAPTER I. 
General Characteristics,— Class Reptilia. 
In ordinary language the term Reptile is applied indifferently to such creatures 
as crocodiles, tortoises, lizards, snakes, frogs, and salamanders, hut by the 
naturalist it is used in a more restricted sense, and includes only the first 
four of these, together with a host of extinct types; while the frogs and 
salamanders, with certain other forms, both living and extinct, on account of 
important structural differences, constitute a class by themselves, known as the 
Amphibians, and bearing the same rank as the class of Reptiles. To an ordinary 
observer there would seem but little in common between a scaled lizard or snake, 
a cuirassed crocodile, and a carapacecl tortoise, on the one hand, and a feathered 
bird on the other. Nevertheless, as we have had occasion to mention at the close 
of the preceding volume, the connection between Reptiles and Birds is exceedingly 
intimate,—so close, indeed, that Professor Huxley has termed the latter greatly 
vol. v.—i 
