200 Dr Hibbert on the Limestone of Burdiehouse 



tf The heart also has not the appearance of the heart of an 

 ordinary fish. It is destitute of that inflation, so characteristic 

 of fish, called Bulbus-aorticus, and has rather the aspect of the 

 heart of a reptile." 



Such is the important information transmitted me by M. 

 Agassiz relative to the Lepidosteus. 



That the animal should have been found to possess lungs is 

 a circumstance which may be availed of in certain geological spe- 

 culations, and upon which some few remarks will be made here- 

 after. In the mean time I may observe, that, if the presence of 

 lungs in their very complicated structure deserve to be consider- 

 ed as a reptilian character, which it is usually supposed to be, the 

 Lepidosteus, instead of being regarded as a sauroid fish, rather 

 deserves the appellation of a finny reptile. 



But without insisting upon the propriety of the latter term, 

 which, on account of other points of anatomical difference, par- 

 ticularly the form of the jaw, would be disputed, it may be, last- 

 ly, remarked, that the teeth, the scales, and various large frag- 

 ments of bones which have been discovered at Burdiehouse, will 

 be referred to an animal bearing the greatest affinity to the Lepi- 

 dosteus, although far larger. 



NOTES TO SECTION IX. 



M. Agassiz, in his " Recherches sur les Poissons Fossiles," has given a draw- 

 ing of the Lepidosteus, of which the wood-cut of this Memoir is a reduction. But 

 in the present incipient state of his work, a full description of the animal has not 

 yet appeared. 



Soon after my Memoir had been read to the Royal Society of Edinburgh, in 

 which I had supposed that a saurian animal was indicated by the teeth and scales 

 which had been discovered at Burdiehouse, I obtained a glance only at the first num- 

 ber of M. Agassiz's work, in which the Lepidosteus was figured ; — (for my own sub- 

 scription copy had been slow in arriving.) I remember having been struck with the 

 animal's crocodilian appearance, which was the only impression I then felt, as I had 

 not been able to subdue the conviction in my own mind, that the monster which pos- 

 sessed teeth like those which were found at Burdiehouse, must have been as complete- 

 ly a saurian reptile as the Gavial of the Ganges. 



7 



