198 S. R. PATTISON, F.G.S. 
through by the South Devon Railway. These are seen in the 
ascent westward from Newton Abbot; and, spreading out, they 
form the exquisite bay of Babbicombe and the headlands and 
heights of Torquay. ‘They display great beds of coralline 
stone, which furnish the workers of the district with beauti- 
fully-veined ‘‘ Devonshire Marble.” 
There are found.here about fifty-two specimens of corals, 
and they all exclusively belong to this epoch of life; not 
one of them is to be seen in the preceding Silurian, and 
not one of them passes into the subsequent Carboniferous 
strata. 
Movuntain-LImMEstone RE&EFs. 
Again setting sail, we soon arrive at another reef. It 
might reasonably have been expected that the shallow 
islands on which grew the tropical vegetation now forming 
our coal-beds would be accompanied seaward by corals, 
which would assimilate them to the islands of the Northern 
Pacific. This is the case. Thus we have an interrupted reef 
extending from Somersetshire to Northumberland, along the 
line of which coralline strata are inter-stratified with shales 
(compressed mud), and grits (compressed sand). 
The common corals of the great coal-limestone are Itho- 
strotion, Lithodendron, Syringopora, Lonsdalia, Zaphrentis, 
and Cyathophyllum. There are altogether in the British area 
one hundred and forty-four species of Carboniferous limestone 
corals, not one of which reappears in the next overlying 
formation, nor in any other. 
JuRASSIC REEFS. 
Our next stopping-place will be on the yellow Bath building- 
stone, extending from Whitby to Weymouth. The geo- 
logical formation is called the Oolite (its grains being similar 
in shape to small eges or roe), or the Jurassic, from its pre- 
valence in the Jura Mountains. Itis a series of sandbanks, 
now converted into freestone; mud, now turned into shale ; 
and limestone, due principally to shells, and sometimes corals. 
In many places along the line it is evident that these former 
sandbanks were anciently crowned with coral formations. 
These are so prevalent in one entire series that the rock is 
named the Corallian. 
Mr. Etheridge enumerates not less than two hundred and 
thirty-six species of coral which have left their marks in the 
Jurassic rocks of England. 
