overlying unconf ormably for some distance directly the Ardros- 

 san Marbles. Its thickness seems nowhere considerable, 20 

 feet being probably the maximum. Throughout the whole 

 extent of this sandstone no fossils have been observed, except 

 some holes resembling those of Pholads. 



South of Parara Station, Sections 31, 22, 21, &c. (fig. 1), 

 some peculiar strata intervene between the " Ardrossan Sand- 

 stone" and the Marbles, viz., a variegated and a dark-coloured 

 limestone, and white and yellow marbles (fig. 3), conformable 

 with the " Ardi'ossan Sandstone" and each other, but unconform- 

 able to the marbles. The planes of stratification are so obliterated 

 in the exposed portions, that their angle of dip has only been 

 surmised from the general agreement of their, exposed faces in 

 vertical distance from each other and the "Ardrossan Sand- 

 stone," in any section from E. to W. But this is not the case in 

 the direction IS", to S. ; on the contrary, here the lowest bed 

 appears first on the summit of the hill in Section 31 (see 

 fig. 1), and subsequently the others, attaining gradually larger 

 dimensions. In Section 21, to which only my observations 

 extend, the lower white and yellow crystalline limestones 

 occupy the lowest depressions, concealing the marbles entirely. 

 ]Sot having at all observed it further south, it seems to be of 

 local occurrence only, perhaps filling up an ancient valley or 

 basin ; but my observations are not sufficient to pronounce a 

 decided opinion. Both varieties of the upper marbles contain 

 distinct fossils and abundantly minute fragments of such, but 

 the upper one by far the most, conspicuous among which occurs 

 a trilobite, and coral structure appears to perfection in sea-rolled 

 pebbles, when the fossil shows in beautiful contrast of colour 

 upon the smooth surface. Professor Tate holds the tentative 

 opinion that the fossils ar,e of Lower Silurian age. The dense, 

 light-coloured marble seems to contain no fossils. 



Pee-Sii/trta:".*. 

 The " Ardrossan Marbles " form the basement rock from 

 Ardrossan to Muloowurtie Point, along the coast. They 

 consist of yellowish or pink coloured (not variegated) saccharoid 

 limestones (figs. 2 and 3) with well-developed jointing and 

 obliterated stratification. At the surface disintegrated to a 

 rubble, a short distance below they form large solid blocks, 

 seemingly well adapted for ornamental building material, 

 being capable, on account of their fineness and density, of 

 receiving a beautiful polish: — especially the pink variety. An 

 almost limitless supply could easily be obtained. At Muloo- 

 wurtie Point, where it forms the foot of the cliff at and below 

 sea level, this limestone is inter stratified with a curious cellular 

 iron ore, assuming, by atmospheric and wave action, a metallic 



