200 S. R. PATTISON, F.G.S. 
4, Some of the Flower-corals (Cyathophyllide). 
5. Madrepores, Brain-stones, and Free corals. 
Among those genera which characterise successive rock- 
formations are the following :— 
Zaphrentis. 
Heliolites, &c. 
Halysites, Favosites. 
Monticulipora, Aulopora. 
Syringopora, &c. 
Cyathophyllum, Heliophyllum. 
Acervularia. 
Strombodes, Stromatopora. 
Favosites, &c. 
Lithostrotion, Lonsdalia. 
Cyathophyllum. 
Amplexus, Syringopora. 
Montlivaltia, Astrea, Isastriea. 
Theosmilia, Thamnastreea. 
Lower Silurian 
Upper Silurian 
Carboniferous 
Jurrassic 
Coralline Oolite 
: 
Devonian . 
S 
( 
) 
’ 
Cretaceous Parasmelia, Syndelia, Stephanophylha. 
Eocene Cup-corals. 
Pliocene Cup-corals.* 
Lessons or THE REEFs. 
Have the corals anything to say on the subject of HKvolu- 
tion,—the great natural history question of the present day ? 
Do they show by their structures that they were evolved 
from previous forms, that they changed with the ages in 
conformity with law, or must we say to those who thus 
express themselves,— 
‘There are more things in heaven and earth, Horatio, 
Than are dreamt of in your philosophy ” ? 
Regarding their succession, do we find the survival of the 
fittest, or proof of the change of one form into another by 
slow modification under the action of their surroundings? 
Surely they can tell us something about these matters; they 
have lived long, and passed through many revolutions, their 
features are fine enough to preserve traces of all the vicis- 
sitades to which they have been subjected, and their forms 
are as definite as geometry itself. Our conviction is that 
* For full information see the works of the accomplished leaders in this 
department, Professor Duncan, Dr. Nicholson, and Mr. Tomes ; and Mr. 
Etheridge’s volume of Phillips's Geology. 
