QUESTIONS. 345 



duction in this country? What is said of Triassic plants? What of 

 Triassic coal ? How did the atmosphere differ from what it was up 

 to the Carboniferous age? What animals were consequently now 

 introduced ? 



239. What kinds of mammals were introduced? What kinds of 

 fishes ? What is said of the Mollusks ? What is the Lily Encrinite ? 

 What is said of the Reptiles ? Describe the Labyrinthodon. 



240. What is said of the name Cheirotherium ? What of the teeth 

 of the Labyrinthodon ? 



241. What of the tracks of Triassic animals? What of the slab 

 represented in Fig. 141 ? What of the Brontozoum giganteum ? 



242. What of the track represented in Fig. 143 ? What of the 

 stone fossil book ? 



243. What are some of the notable localities of trap rocks in this 

 country ? As they were thrust up, what effect resulted in the adja- 

 cent rocks ? What is said of their systematic arrangement ? 



245. What is said of the vegetation of the Triassic period ? State 

 the facts about the Portland dirt-bed. 



246. Give in full what is said of the animals of this age. 



247. What were the most prominent of the mollusks of this pe- 

 riod? What is the class to which they belong, and what are the 

 characteristics of the class ? 



248. What is said of the Ammonites ? What of the Belemnites ? 

 What of the Ichthyosaurus ? 



249. What of the Plesiosaurus ? 



250. What of the Pterodactyl ? What has been the common opin- 

 ion about the nature of this animal ? What is Agassiz's opinion, and 

 what are his reasons for it ? 



252. What is probably the truth about the flying of the Pterodac- 

 tyl ? What is said of the Dinosaurs ? 



253. What are the rocks of the Cretaceous system in Europe and 

 Asia? What in this country? What is said of the Green-sand? 

 What of chalk? What of the localities of the Cretaceous system ? 



254. How was chalk formed? Of what is it constituted as shown 

 by the microscope ? What is said of chalk-marks ? What is the act- 

 ual difference between chalk and other forms of carbonate of lime ? 

 What is said of deposits of chalk now going on ? 



255. What is said of the presence of flint in chalk ? What of the 

 Xanthidia ? 



256. What of the shell prisms in flint? What of the flinty spicula 

 from sponges ? 



258. What of the agency of sponges in the Cretaceous period ? 

 What of the animals of that period ? What of the change in the 

 forms of the Ammonites? 



P2 



