FOSSIL CORALS. 



92 



obtained from this bed. Steeple Ashton (in Wilt- 

 shire) and Malton (in Yorkshire) are well-known 

 coral collecting grounds. At the former place we 



Fig. jz. Montlivaltia trochoides (Inferior 

 Oolite). 



Fig- 73- Isastrcea oblonga 

 (Portland stone). 



get Thecosmilia annularis a fine, branching, shrub- 

 like coral, about two feet high. The Portland stone 

 at Tisbury contains a bed of 

 Isastrcea oblonga a lovely 

 coral, completely silicified. 

 When splinters of this are 

 rubbed down to a thin 

 shaving, and then mounted 

 on glass for the microscope, 

 they form exquisite objects, 

 showing every line and trace of the coral structure. 



The charming neighbourhood of Stroud is one of 

 the best Oolitic coral-grounds in England ; certainly it 

 is so as regards varieties, and perhaps also for numbers 

 of specimens. The student who visits the neighbour- 



Fig. 74. Thecostnilia annularzs 

 (Coral Rag). 



