198 Dr Hibbert on the Limestone of Burdiehouse 



and rivers of the warm regions of America. To this animal the 

 name of Lepisosteus, or, according to M. Agassiz's altered no- 

 menclature, Lepidosteus has been given, — a term significant of 

 the hard, bony, and crocodilian character of its scales. 



With this sauroid, yet finny inhabitant of the waters, M. 

 Agassiz had already, as far as related to certain comparatively 

 small sauroid fish enclosed in the carboniferous group of rocks, 

 found much analogy. He had, however, still to learn, that sau- 

 roid fish of even gigantic dimensions were referable to the self 

 same geological epoch. The knowledge of this important fact 

 he first acquired at Burdiehouse. 



The Lepidosteus, of which the foregoing is a representation, 

 admits of three species, the Lepidosteus spatula, the L. Gavial, 

 and the L. Robolo. 



The Lepidosteus Gavial is so named from its actual resem- 

 blance to the crocodilian animal of the Ganges. " This fish," 

 observes a naturalist, " has the greatest relations of external 

 likeness with the saurian reptile, whence it has derived its 

 name. These traits of resemblance are instantly recalled to the 

 mind of the observer by the form of the head of the animal ; — 

 by the very great elongation of its jaws, by their little breadth, 

 and by the furrow longitudinally hollowed out on each side of 

 the upper jaw ; — by the irregular osseous pieces, carved, radiated, 

 and strongly articulated with each other, which envelope its 

 head, or which compose its opercules ; — by the quantity, the 

 form, and the inequality of the teeth : — by the position of the 

 orifices of the nostrils at the end of the snout ; — by the situation 

 of the eyes, which are placed very near the angle of the mouth ; 

 — by osseous scales which, being distributed over the whole of 



