XXIU HUGH MILLER, 



contain only the third i)art of the Old Red Sandstone, which 

 but a few years ago was supposed to be the least productive 

 in fossils of any of the geological formations, yet it furnishes, 

 according to Mr Miller, more fossil fish than every other geo- 

 logical system in England, Scotland, and Wales, from the 

 Coal Measures to the Chalk inclusive. It is, in short, ^Hhe 

 land of fish" and " could supply with ichthyolites, by the 

 ton and by the ship-load, the museums of the world." Its 

 various deposits, with the curious organisms which they in- 

 close, have been upheaved from their original position against 

 a granitic axis, about six miles long and one broad, " forming 

 the great back-bone of the western district of the island 

 Pomona ; and on this granitic axis, fast jambed in between 

 a steep hill and the sea, stands the town of Stromness." 



The mass or pile of strata thus uplifted is described by Mr 

 Miller as a three-barred pyramid resting on its granite base, 

 exhibiting three broad tiers, — red, black, and gray, — sculp- 

 tured with the hieroglyphics on which its history is recorded. 

 The great conglomerate base on which it rests, covering from 

 10,000 to 15,000 square miles, from the depth of from 100 

 to 400 feet, consists of rough sand and water-worn pebbles ; 

 and above this have been deposited successive strata of mud, 

 equal in height to the highest of our mountains, now con- 

 taining the remains of millions and tens of millions of fish 

 which had perished in some sudden and mysterious catas- 

 trophe. 



In the examination of the different beds of the three-barred 

 formation, our author discovered a well-marked bone, like a 

 petrified large rooting nail, in a grayish-coloured layer of 

 hard flag, about 100 yards over the granite, and about 160 

 feet over the upper stratum of the conglomerate. This sin- 

 gular bone, which Mr Miller has represented in a figure, was 

 probably the oldest vertebrate organism yet discovered in 

 Orkney. It was 5| inches long, 2^ inches across the head. 



