BY PROFESSOR STEPHENS, M.A., F.G.S. 1177 



" the outer surface is sculptured by radiating furrows, except at so 

 much of the marginal part as is overlapped by the lateral pieces.'' 

 (Owen, I.e. p. 179\ This fact of course shows that we have the 

 upper or inner face of these structures exposed, and that their 

 external or downward aspect is hidden. It follows then that, 

 while we have the upper surface of the Head preserved, the 

 anterior part of the vertebral column, and the whole upper surface 

 of the body have been more or less engaged in the counterpart 

 stone, which is lost ; that we see in our specimen the interior 

 surface of the Thoracic plates displayed by the removal of the 

 upper part of the body ; and have a view, from above, of all the 

 vertebrae and ribs, except some few of the anterior joints, a& 

 far as, and including, the indications of a pelvis or equivalent 

 support for a weak hinder limb. The Amphibian, therefore, lies 

 flat upon its belly, while the fishes which are associated with it 

 on the slab are naturally laid flat upon their sides. 



Before proceeding further it must be clearly understood that 

 the greater part of the details which I am about to describe 

 cannot be made out by a hurried observation, nor even by the 

 most careful examination if made on one single occasion. The 

 varying illumination which we receive under various conditions of 

 the atmosphere is found, in such almost obliterated inscriptions, 

 to bring out from time to time particulars of form, relief, sculpture, 

 and colour which otherwise, as under a perfectly clear sky and in 

 bright sunlight, remain invisible. Points and lines which become 

 clearly distinguishable, if not distinct, at one moment, seem to 

 vanish as suddenly as they appear, and one may look in vain 

 to-day for forms which yesterday might be measured and drawn 

 without difficulty. It follows that the figure which accompanies 

 this paper is fairly entitled to an amount of consideration which 

 one would not presume to claim under circumstances of a less 

 perplexing character, and that it should be judged not upon a 

 single comparison with the original, but after a long series of 

 examinations on different days, and at different hours. It is not 

 probable that many persons will take this trouble. Nor indeed is 

 it necessary. If these drawings are correct, or so far as they are- 



