from St. Tho- 

 mas's Head. 

 The repetition 

 of the expo- 

 sures is due to 

 several small 

 faults running; 

 at right angles 

 to the coast- 

 line. 



( a ) In the 

 first or western- 

 most exposure, 

 bedded cri- 

 noidal lime- 

 stone, with 

 abundant Za- 

 phrentis, is suc- 

 ceeded by an 

 alternation of 

 limestone and 

 red or green 

 tuffs, in which 

 organic remains 

 are frequently 

 embedded, and 

 well - marked 

 lapilli are abun- 

 dant. Then 

 comes the ' pil- 

 lowy,' much - 

 altered, amyg- 

 daloidal basalt, 

 which has in 

 parts degene- 

 rated into a 

 brown sandy - 

 looking mate- 

 rial, wherein 

 little can be 

 made out ex- 

 cept the amvu- 

 dules. This is 

 followed by 

 further alter- 

 nations of 

 limestone and 

 tuff passing up 

 into the mas- 

 sive limestone. 



