§ 6. GENERAL VIEW OF THE OOLITE AND LIAS. 491 



cephalopoda of extinct forms, Crustacea, fishes, and reptiles; 

 and the plants belong to many species of fuci, algse, &c. 



Those of the land consist of such as were transported 

 into the ocean by rivers and currents, namely, trunks and 

 branches of coniferous trees, cycadeous plants, ferns, &c. : 

 sometimes in the state of lignite, and coal. The animal relics 

 are principally of insects, with bones and teeth of numerous 

 reptiles ; and of two or three genera of small terrestrial 

 mammalia. Evidence is thus afforded of the existence of 

 countries clothed with a luxuriant vegetation, and inhabited 

 by a prodigious number of reptiles, and a few warm-blooded 

 quadrupeds. 



I shall also comprise in this Lecture a notice of the 

 Permian formation, that the Carboniferous system may 

 be considered in a separate discourse. 



6. General view of the Oolite and Lias. — The 

 Oolite formation may be described as consisting of three 

 principal argillaceous, and of an equal number of calcareous 

 deposits. The leading subdivisions of these strata as they 

 occur in England, and the names by which they are gene- 

 rally distinguished, are expressed in the following table. 

 The Lias is included, for though in conformity with the 

 usual geological classifications this group of strata is placed 

 as a separate formation in the synopsis (p. 202) ; we shall 

 find it convenient, and I believe more in accordance with 

 the origin and nature of the deposits, to comprise it in a 

 general survey of the Oolitic or Jurassic system.* 



* In the Map, PL I. vol.i. the Oolite and Lias are denoted by the 

 same colour and number (4). 



