360 



GENERAL ZOOLOGY 



prey with only the tip of the snout exposed, or concealed in 

 the vegetation at the edge of the water. They feed at night, 

 and during the day bask in the sun on sand-banks or on logs. 

 Geological Development of Reptiles. We have seen (p. 345) 

 that during the Age of Amphibians a great part of the 

 interior of North America was one vast swamp, in which 

 stretches of black water alternated with drier areas covered 

 with the characteristic vegetation of the period, the whole 

 bathed in the heat of a tropical climate. Under conditions 

 similar to these the reptiles first came into existence in the 

 latter part of the Carboniferous Age. They developed in num- 

 bers, size, and form, and became in the succeeding period so 

 characteristic a part of the world's fauna that the age is 

 named, from them, the Age of Reptiles. This forms the third 

 great division of geological time, called Mesozoic Time, or the 



FIG. 185. Ceratosaurus 



Era of the Mediceval Forms of Life. In North America the 

 era began with the upheaval of the Appalachian system of 

 mountain ranges, as stated on page 347. During a part of 

 the era great areas in the south and west were submerged 

 beneath the ocean. 



