Geology and Faleontology. 639 
marked approximately the same glacial period, which probably 
occurred towards the close of the Palæozoic, and resulted in the 
extinction of many of its peculiar forms. The peculiar flora of 
the Newcastle beds and of the Indian Damudas proved the exist- 
ence of botanical provinces in past ages. 
structure of its ambulacral areas; Leiopneustes antiquus has no 
fascioles ; and Brissospatangus canmonti may be known by its 
very excentric anteriorly placed ambulacral summit and its short, 
transverse and widely separated anterior paired ambulacra, situated 
ina depression. The Brissidz appear in the Cretaceous, reach their 
maximum in the Tertiary and still persist in most seas. The. 
Cretaceo-Eocene limestones of the Jaulan and Hauran regions, 
described by Mr. G. Schumacher, seem to have been deposited, 
upraised and largely denuded, before the volcanic lavas of the 
district were forced out. As this movement and denudation took 
place in the Miocene epoch, the volcanic eruptions may be re- 
ferred in the main to the succeeding Pliocene. The so-called 
delta of the Orinoco, according to A. Ernst (Nature, Feb., 4th), 
raco and many of the lagoons in the provinces of Cumana 
and Maturin. The southern branch is the old river channel, but 
when the land on the left bank sank gradually towards the north, 
Source of the bitumen and other carbo-hydrates of the vicinity. i 
a o * 
Matter must have been buried with the sunken land to form the _ 
