154 



RAMBLES AND REVERIES. 



FIG. 41. Thecosmilia 

 annularis. 



reaching only an average of about fifty feet, but it has 



yielded some fifteen species of fossils. Thecosmilia 

 annularis (Fig. 41) is a 

 very pretty, large-branch- 

 ing coral of this zone, and 

 is obtained from the Wilt- 

 shire beds. Oolitic corals 

 are also plentiful at 

 Malton, in Yorkshire, and 

 near Stroud, where there 

 occurs an ancient "barrier 

 reef" crowded with 



Thamnastraa, Isastrcea, Thecosmilia, etc. 

 The Cretaceous System follows the Oolitic, and is 



distinguished for the great number of single corals 



which its various strata 



contain. As an example 



of these we present an il- 

 lustration of Smilotrichus 



granulatus (Fig. 42). 

 The Tertiaries of Britain 



afford very few corals. 



Several kinds are obtained 



at Bracklesham, in the 



New Forest, at High 



Cliff, in the Isle of Wight, 



and in the London Clay 



of Sheppey. Litharcea 



(Fig. 43), an Eocene ex- 

 ample, is very common. 



This brings us to the close of our review of the 



geological history of corals, and it now remains only 



FIG. 42. Smilotrichus 

 granulatus. 



