Fingal and East Coast. 35 



sandstone ; and I obtained there a few fossil shells 

 imbedded : but these were rare, or altogether wanting, 

 just as the dist.mee from superincumbent limestone or 

 its place increased. 



The superior beds become still thicker and more 

 compact, acquiring somewhat of a columnar structure in 

 the large; but they soon yield again to thinner argillaceous 

 layers of a schistose structure, in which are to be found 

 casts and impressions of Spirifers, Serpulce, and Poli/- 

 parice. These fossiliferous clayey beds merge in lime- 

 stone of a very hard, compact, and crystalline structure, 

 of a colour varying locally from yellowish and greyish 

 white to pink, and replete with casts and impressions of 

 corals, Spiriferce, Terehratulcs, Pectinides, and occasion- 

 ally of Encrinites. 



The aggregate thickness of the slightly inclined seams 

 between the vertical clay-slates and the limestone appears 

 to be about 200 feet. The limestone has not presented 

 itself to me any where in masses deeper than 40 or 50 feet. 



When burnt, it yields an excellent lime ; and it is pro- 

 bably identical with the limestone formation which skirts 

 Mount Wellington, cropping out at the Cascades, at 

 Ancanthe, and Tolosa, and upon the road-side in the 

 vicinity of New Norfolk, again to make its appearance 

 upon the Dromedary, on the opposite side of the River 

 Derwent. 



On the western bank of a streamlet which flows 

 perennially through the little crescent-shaped valley, 

 described as in front of TuUochgoruni House, the lime- 

 stone has been removed by natural agency from the beds 

 of clay, conglomerate, and clayeysandstone, just where the 

 shells become abundant, and it is replaced with a capping 

 of greenstone. This partial denudation could only have 

 jbeen accomplished by the action of water, and the super- 

 vention of greenstone must have occurred subsecjuently. 



d2 



