172 THE CRUISE OF THE BETSEY ; OR, 



curled when the last pang was over. In various places in 

 the neighbourhood the ichthyolites are found in situ in their 

 coffin-like nodules, where it is impossible to trace the relation 

 of the beds in which they occur to the rocks above and be- 

 low ; and I had suspected for years that in at least some of 

 the localities, they could not have belonged to the lower plat- 

 form of death, but to some posterior catastrophe that had 

 strewed with carcases some upper platform. I had thought 

 over the matter many a time and oft when I should have been 

 asleep, for it is marvellous how questions of the kind grow 

 upon a man ; and now, selecting as a hopeful scene of inquiry 

 the splendid section under the Northern Sutor, I set myself 

 doggedly to determine whether the Old Red Sandstone in 

 this part of the country has not at least its two storeys of 

 organic remains, each of which had been equally a scene of 

 sudden mortality. I was entirely successful. The lower 

 ichthyolite bed occurs exactly one hundred and fourteen feet 

 over the great Conglomerate ; and three hundred and eighteen 

 feet higher up I found a second ichthyolite bed, as rich in 

 fossils as the first, with its thorny Acanthodians twisted half 

 round, as if still in the agony of dissolution, and its Pterich- 

 thyes still extending their spear-like arms in the attitude of 

 defence. The discovery enabled me to assign to their true 

 places the various ichthyolite beds of the district Those in 

 the immediate neighbourhood of the town, and a bed which 

 abuts on the Lias at Eathie, belong to the upper platform ; 

 while those which appear in Eathie Burn, and along the 

 shores at Navity, belong to the lower. The chief interest of 

 the discovery, however, arises from the light which it throws 

 on the condition of the ancient ocean of the Lower Old Red, 

 and on the extreme precariousness of the tenure on which 

 the, existence of its numerous denizens was held. In a sec- 

 tion of little more than a hundred yards there occur at least 

 two platforms of violent death, platforms inscribed with un- 



