BY JAMES C. COX, M.D., F.L.S., ETC. 275 



of a coarse green sandstone, with scales of mica dispersed through 

 it, which will, I believe, turn out to be scales of graphite. This 

 rock is so coarse as almost to pass into a grit. Immediately 

 below this there were about ten feet of a very hard blue sandstone 

 very fine and dense in the grain. For thirty feet below this, a 

 very hard blue sandstone was found, with dark partings of black 

 shale. These black shale partings were full of ^phjlotheca (fossil 

 coal plants and leaves), and when broken had a very characteristic 

 resinous fracture. Below this came a dark sandstone with broad 

 streaks of carbonate of lime running through the core longitudin- 

 ally, causing it to split ; this bed was about fifteen feet thick. 

 Below this was found a rock of only two feet in thickness, but of 

 a very interesting character, made up of broken fragments varying 

 greatly in colour, but, as a rule, having the character of fragments 

 of a greenish-slaty rock. 



Now for the first time below this thin band the Estheria shells 

 showed themselves. They were found in dark shaly streaks of 

 irregular thickness, which were found to separate this layer of 

 rock, which was a very hard sandstone, having an exceedingly 

 fine grain. This bed was, as I have said, composed of dark shaly 

 streaks and sandstone partings, the sandstone preponderating 

 throughout, and was about 30 feet thick. We have now reached 

 a depth of 1523 feet. 



It will not be uninteresting here to mention that though this 

 shell, if shell it may be called, was first struck at Moore Park, 

 at a depth of 1523 feet, it was not found in the core raised at 

 Port Hacking till they had reached a depth of 2160 feet. The 

 two cores correspond wonderfully up to a depth of 1483 feet. The 

 Estheria bed struck at Moore Park was altogether absent at Port 

 Hacking, but there at the depth mentioned it was found in exactly 

 the same character of shaly rock, ^t Port Hacking the drill 

 entered quite a different class of rock at the depth at which the 

 Estheria were found at Botany, it being a conglomerate of no less 

 than 480 feet in thickness. It is difficult to account for this great 



