144 Rev. A. Sedgwick and Mr. Murchison on Deposits contained between 



racter of the Lepisosteus in the shape of its scales. The ventral fins are placed 

 very much behind the body, and the anal fin is almost below the dorsal fin, 

 which is consequently placed very far backward. We have not seen enough 

 of the head, nor sufficient of the caudal fin, to judge of its form ; but from 

 what remains of this fin, M.Valenciennes is inclined to think it was forked, 

 which peculiarity would distinguish this fish from the Lepisosteus, and would 

 bring it nearer to the genus Amia. He proposes to name this genus Osteo- 

 lepis ; and as two species are indicated by the different size of the scales in 

 each, they may be distinguished by the names Ostcolepis macrolcpidotus, and 

 Ostcolepis microlepidotus. 



The naturalists who have examined these fish are disposed to think that 

 they were the inhabitants of fresh-water ; a conjecture which seems strength- 

 ened by the fact, that the remains of a tortoise nearly allied to Trionyx, are 

 found both in the bituminous schists of Caithness and the Orkneys*. We 

 found an imperfect fossil stem of a plant and other traces of vegetable matter 

 among the ichthyolites, but never observed a single fossil shell or zoophyte in 

 any part of the schistose formation. 



§ 3. Secondary Deposits on the Shores of the Murray Firth. 



We now proceed, in the order pointed out in the introductory part of this 

 paper, to describe the secondary deposits on the shores of the Murray Firth. 

 The range of the old conglomerates from the granitic mountains which sepa- 

 rate Caithness from Sutherland, down to the highest parts of the Beauly Loch 

 and of Loch Ness, and from thence along the north coasts of Nairn, Elgin, 

 and Banff, has already been given with sufficient detail ; and, between this 

 line of range and the shores of the Murray Firth, are comprehended all the 

 rocks which now fall under our notice. An inspection of the map will show 

 that they are bounded to the north-west by the mountains of Sutherland, 

 Ross, and Inverness ; and to the south-east by the higher regions of Nairn, 

 Elgin, and Banff: from which facts, independently of more direct evidence, 

 we should be led to infer, that they had been deposited in a great trough of 

 the primary formations, which expands towards the north-east, and declines 

 into the Murray Firth, and, towards the south-west, is prolonged across the 

 mainland of Scotlandf- A detailed examination of the secondary formations 



*' Plate XVI. fig. 6. 



t It is obvious from the above statements, that the conglomerates must have been formed upon 

 a very uneven surface of the more ancient rock ; and that a part, at least, of the great trough 

 which affords a passage to the Caledonian canal must have existed before the commencement of 

 the secondary deposits, and at a time when the greater part of Scotland was probably sub-marine. 

 The conglomerates could not by any conceivable force have been piled up into mountains three 



