Geology of England and Wales,” &c. 219 
characteristic ; consisting of bones of the Ichthyosaurus 
and numerous shells. 
7 * 
Lower Division of Oolites. 
This division far exceeds the two preceding, in thickness 
and importance. The subdivisions, which might with 
propriety be made. in it, are so numerous, that the writers 
very wisely refer the whole to two sections, viz. its upper 
and: lower beds: all the upper beds being subordinate to 
the great oolite; and the lower, to the calcareo-siliceous 
send, which forms their base. Viewed generally, both 
these’ series of beds consist of one vast oolitic mass, resting 
upon calcareo-siliceous sand. These oolitic beds, howev- 
er, embrace several varieties, characterized principally by 
being more or less argillaceous. These are denomina 
ina descending order, Cornbrash, Stonesfield Slate, Forest 
Marble, and Great Oolite. The inferior members of the 
third, or lower system of Oolites, are the Fulter’s Earth, In- 
ferior Oolite Sand, and Maristone. The inferior is distin- 
guished from the Great Oolite, by the larger proportion of 
broww oxide of iron, that is disseminated through its mass. 
be sand and sandstone are slightly calcareous, highly 
ferruginous, and frequently micaceous ; containing but few 
sils. The marlstone. is. sandy, gritty, micaceous, and 
of a green color; preseating but few organized remains, 
The lower division of the oolitic series, however, 1s pe- 
culiarly interesting for the richness and variety of its fos- 
. The testacea are very abundant: and a more com- 
plete and extensive list of these is given in the work before 
us, than of any other formation. Echinites, encrinites, 
corralloides, madrepores, tubipores, millepores, and alcyo- 
nia. are also found. But thé Stonesfield slate, which 1s 
with great probability referred to the Oolitic series, 1s most 
remarkable for its petrifactions. ey ongur A Ineaes of 
idelphys, one of the Opossum tribe ; an Immense — ’ 
resembling the Tbh be, 40 feet long and 12 feet high; pe 
or three species of tortoise; teeth, palates, and vertabrae 0 
fishes; leg and thigh bones of birds; two of three species 
of Coleopterous insects ; two or three varieties of the crab, 
or lobster; and ferns, flags, and mosses. This remarkable 
