22 



E. Greenly — Sanddonc Pipes. 



collapse in this bed of sandstone ; indeed, tlie upper surface of the 

 bed is in most cases gently domed upwards over tlie openings of the 

 pipes, so as to present a hummocky surface on the foreshore. lu 

 some cases also there is a domed joint or crack in the sandstone over 

 the head of the plug. 



SSE 



NNW . 



Fig. 2. — Diagram Section at Dwlbax Point. 

 a, Piped Limestone ; /3, Sandstone ; 7, Shale ; S, Upper Limestone. 



The larger pits seen at Dwlban Point are about 6 feet in diameter 

 at the top, and can be traced to a depth of about 5-6 feet. But 

 about 230 yards to the south, at an inland crag across the debris of 

 some ancient quarries, is a section showing a pipe no less than 

 12 feet in depth. (Fig. 3.) The rock pierced by the pipe is a VQvy 



¥10. 3. — Lauge Py'K IX Inland Cliff. 

 a, Cherty Limestone ; /3, Sandstone ; 7, Upper Limestone, 

 massive grey, crystalline Limestone, with lines of chert nodules, and 

 the material of the pipe is in connection with that of the base of 

 a sandstone whose normal thickness is about 8 ^eet. Overlyin<r this 

 is another Limestone about 10 feet thick, rather fine and dark, and 

 poor in fossils. Except at the pipe the sandstone lies in perfect 

 conformity with both Limestones. It is a white, hard rock, mostly 

 fine, but with some lines of pebbles. The fuunel-sliaped pipe, whose 



