644 THE WONDERS OF GEOLOGY. Lect. VI. 



A reddish marble, beautifully marked by the sections of 

 the enclosed Tubipores, and susceptible of a good polish, 

 is quarried in some parts of Derbyshire (Lign. 143, Jig. 2). 

 Mr. Parkinson ascertained that the hue of this marble is 

 dependent on the original colour of the coral, which, pro- 

 bably, like the recent tubipore (ante, p. 619), was of a rich 

 scarlet hue. 



1. 2. 



3. 



Lign. 143.— Coralline Marbles. 



Fig. 1. Silurian limestone, composed of a species of Syringopora; Dudley. 



— 2. Folished section of a marble formed of Syritigopora strues ; Derby- 



shire. 



— 3. Chain-Coral ( Catenipora cscharoides ); Dudley. 



I have mentioned (ante, p. 609), that the earthy matter 

 of the recent corals, like the phosphate of lime in the bones 



