384 Proceedings of the Royal Society of EdinhtirgJt. 



the reptiles improperly called doubtful reptiles. The lung or swim- 

 ming bladder of the Lepidosteus is not only cellular, but has also a 

 trachea^ which extends the whole length of its anterior surface, and 

 communicates with a glottis, surrounded by ligaments, intended to 

 open and shut it, constituting an apparatus even more complicated 

 than what is found in many reptiles. M. Agassiz also adds, that the 

 heart has not the appearance of that of a common fish : it is destitute 

 of the inflation named bulbus aorticus, so characteristic of fish, and 

 hence has much more the aspect of the heart of a reptile. 



With this fish, in its well marked external characters, M. Agassiz 

 has compared the sauroid relics discovered at Burdiehouse, and, in 

 this inquiry, he has been assisted by the entire head of a large fos- 

 sil fish, preserved in the museum of Leeds. From the aid thus de- 

 rived, he has been enabled to establish a new genus under the name 

 of Megalichthys. With regard to the scattered and disjointed bones 

 found at Burdiehouse, it is conceived that they indicate a distinct 

 species, to which M. Agassiz has some time since given the name of 

 Megalichthys Hibberti. To the remains of another species of the 

 same genus, discovered near Glasgow, and distinguished by a greater 

 flatness of its teeth, M. Agassiz is disposed to assign the appellation 

 of IMegalichthys falcatus. 



December 15. — James Russell, Esq., Vice-President, in 

 the Chair. The following communications were read : — 



1. General Remarks on the Coal-Formation of the Great 

 Valley of the Scottish Lowlands. By Major-General 

 Lord Greenock. 



In this paper the author stated, that although there is sufficient 

 evidence in the mechanical origin and organic contents of the beds 

 (some of them of extraordinary thickness and extent), which form the 

 coal-measures, to prove the pre-existence of much larger tracts of dry 

 land, in connection with each other, than could possibly have been 

 afforded by the older portions of the present countries ; such proofs 

 are altogether wanting when we endeavour to restore, in imagination., 

 what might have been the probable extent of that land, the greater 

 part of which may now lie buried beneath the ocean, or have since 

 been covered by more recent deposits. It appears, however, to have 

 been clothed with a luxuriant tropical vegetation, and sufficiently 

 elevated to have given rise to the rivers and torrents, by which the 

 materials for composing the coal strata had been carried down into 

 the lakes or estuaries, where to all appearance they were deposited. 



The circumstances in which the large fossil trees are seen imbed- 

 ded in the strata of the coal-measures, and other similar phenomena, 

 have led the author to suppose, that these rivers and their estuaries 

 may have been of greater magnitude than would probably have been 

 the case if they had been situated in small islands, according to the 

 opinion of many geologists. The intermixture of terrestrial and ma- 

 rine remains in the same beds, is a strong evidence in favour of their 



