1848.] and on its Coal and other Minerals. 505 



two species of Echinidse and a single tooth resembling that of a shark, 

 which is the only trace of the remains of vertebrata, we had the fortune 

 to discover. 



Compact Nummulite Limestone with Flints. — The compact lime- 

 stone, from its light grey, almost white color, and the great abundance 

 of flint nodules deposited in it in regular layers, together with the 

 appearance of its fossils, which are sometimes incrusted with a white 

 chalk, has a certain resemblance to some of the older members of the 

 cretaceous formation. 



Chemical character of Limestone. — Its fine grained, almost flinty 

 appearance, at first sight induced us to believe it was highly saliceous ; 

 but this is not the case, it being a very pure limestone, rapidly dissolv- 

 ing in diluted acids and leaving a mere trace of clay or mud. Its wea- 

 thered surfaces have a glazed appearance, and present occasionally an ooli- 

 tic structure, which is caused by the numerous nummulites and other 

 foraminifera which frequently form the rock. The influence of these and 

 of the more minute but not less wonderful class of infusorial animals in 

 building up the crust of the earth is well illustrated in the strata of the 

 salt range, all of which appear to be of marine origin, the sea at the time 

 of the formation of the upper deposits having been highly charged with 

 calcareous and saliceous matter, which through, the agency of these 

 minute organisms has been separated from their solutions and deposited 

 in the masses we now behold. This limestone, which for the sake of 

 distinction we will call nummulite limestone, forms the ridge of the hills 

 presenting a steep southern escarpment from 150 to 200 feet high and 

 giving to the range the peculiar white color before alluded to. It pre- 

 sents indistinct marks of stratification, except in its lower part, but re- 

 poses conformably, as far as we could ascertain, on the rocks inferior to 

 it. Its surface, as exposed in the precipices on the southern escarpment 

 of the range, weathers into large cubical masses, which give it the 

 appearance of a wall built of loose fragments of rock, which by their 

 gradual disintegration have fallen down and cover the declivity of the 

 hills over a considerable surface, rendering their ascent a matter of no 

 ordinary labour. 



On surmounting the saliferous strata the saline efflorescence before 

 noticed, as occurring on their surface and on the banks of the small 

 streams which flow down the ravines, entirely disappears, and the water 



