THK LIAS. I 29 



genera occur, though they are sometimes met 

 with in the underlying /one of Ammonites serpen* 



per Lias of Gloucestershire and War- 

 re contains a considerable number of in- 

 sect remains, probably derived from the forests 

 in which the coniferous trees grew, which appear 

 have been allied to the living Axaucaria. 

 •mains of Cycads, such as 

 and - >f a few fen . though 



1 evidence of a land surface as in 



the iriod, the occurrence of insects in 



- which, m the previous period of the 



vield the remains of terrestrial animals, 



w that the physical change which 



Ight the . cnd % and caused the Mid- 



I sands to be superimposed upon it, was 

 tially a bringing I gain in part, by 



I the shallow water condi- 

 - which prevailed m the Trias period. 



:ids, 200 feet m thickness at 

 Bridport, which pass northward into Somerset- 

 Stershire, under the name of 

 M If rd sands, gradually thin away. But since 

 they indicate the same conditions as afterwards 

 ir in the Northampton sands in the mid- 

 dle gland, they may be grouped with the 

 rather than with the Lias. 



