416 



DR. C. GILBERT CULLIS. 



A Series of Diagrammatic Figures illustrating some of the numerous 

 Conditions of Preservation and Types of Mineralisation exhibited by 

 the Corals in different Parts of the Boring. 



(For the purpose of making clear the relations which exist between the various 

 conditions illustrated, the same coral form has been reproduced in all the figures. In 

 this respect, therefore, they are diagrammatic, but in other respects they represent 

 in a fairly accurate manner what is actually seen under the microscope.) 



Fig. 50. — Fresh coral with empty cavities. The 

 coral-substance composed of primary aragonite. 



Fig 51. — Coral-substance aragonite ; cavities 

 filled with fine calcareous detritus. 



Fig. 52. — Coral-substance aragonite ; cavities 

 partly filled with secondary aragonite, depo- 

 sited from solution ; crystals continuations of 

 the coral fibres. 



Fig. 53. — Coral-substance aragonite ; cavities 

 partly filled with fibrous encrusting deposit of 

 secondary calcite ; crystals not continuations of 

 the coral fibres. 



