EXCURSION VI. 129 



skilful mason, or even a mathematician, could produce any- 

 thing more regular or more beautiful." 



Farther on about half-way between the Salt Pans and 

 the " Cock of Arran" several beds of red limestone, rich in 

 fossils, and of red shale, occur. It is interesting to notice 

 the perforations of pholades in the limestone above the 

 level of the present tides, as being a striking collateral proof 

 of that change of level to which we have so often alluded. 

 The beds are so numerous, and the alternations so much 

 like those already noticed, that a description of them would 

 be tedious; but the variety of the fossil contents will amply 

 repay a careful examination. 



These beds are succeeded by a series of sandstones, shales, 

 and fine conglomerates, overlaid in their turn by variegated 

 marls containing nodular ironstone, and by white sandstone. 

 Over the latter, a little way east of the Cock, lie beds 

 of fine red sand, alternating with fine conglomerate, the 

 dip of both being K 65 W., at 23. These beds, with 

 the white and red sandstones which succeed them westwards 

 till the schist is reached beyond the Scriden, are the 

 uppermost members of the whole series, which begins to 

 overlie the old red sandstone near the Fallen Rocks. From 

 their position and mineral character they have been classed 

 as new red sandstone by Murchison, Sedgwick, and Ramsay. 

 Mineralogically, they have a much greater resemblance to 

 lower permian strata than any of the rocks in the southern 

 district; but we refer them, notwithstanding, to the upper 

 carboniferous series, to which they are more closely related 

 by their fossils. 



The Cock of Arran, near which this series begins, is a 

 large isolated mass of sandstone, resting on the beach, a 

 noted landmark among sailors. When seen in front from 

 the sea the block had the form of a cock, with expanded 

 wings, in the act of crowing. The resemblance is now less 

 striking, as the head has been broken off'. Beside this block 

 there are two singular whin dikes close together, on the 



