156 PHILOSOPHICAL TRANSACTIONS. [aNNO 1786. 



differences cannot fail to convince the learned Society of the truth of what I 

 have asserted, about the animal these bones belonged to ; for though we cannot 

 determine exactly the species itself, yet I flatter myself the preceding observations 

 evidently prove that they did not belong to any animal of the crocodile kind. 



§ 8. Another very beautiful specimen, a foot and a half long, and about 10 

 inches broad, I have been induced to add, because it contains the anterior part 

 of the scutum of a very large turtle. Of this Mr. John Hunter has a similar 

 bone from the same mountain in his valuable collection, but sent to him under 

 another name. I am convinced it belonged formerly to a turtle, first, because I 

 have from the same mountain the entire back of a turtle, 4 feet long and 10 

 inches broad, a little damaged at the sides, and a pretty large fragment of an- 

 other turtle, in my possession. 2dly, Because I have a similar one, but so 

 placed within the matrix as to show the inside, which is perfectly similar to the 

 inside of that piece in the back of a large turtle I got in London, by the favour 

 of Mr. Sheldon. 3dly, Because I have among these bones the lower jaw-bone 

 of a very large turtle, of which the crura, though not entire, are 7 inches long, 

 and distant from each other 6 inches; the thickness is equal to 1-l inch. All 

 these fragments prove the frequency of turtle bones among the other fossil bones 

 found in the mountain near Maestricht. 



Dr. Michaelis wrote to me some time ago, that the above-mentioned fragment, 

 in Mr. J. Hunter's Collection, belonged to a bird ; which I could hardly believe, 

 as I never had seen in any collection whatever, either in London, Paris, Brussels, 

 Gottingen, Cassel, Brunswick, Hanover, or Berlin, nor in my own country, 

 any fossil bone belonging to a bird. I know there is a small one described in 

 the Abbe Rozier's Journal de Physique, for March 1782, which is at present 

 in the collection of M. D'Arcet, at Paris. I expect also from Montmartre a 

 small leg of a petrified bird ; but these are the only ones I have ever heard of, 

 those of Stonefield, near Woodstock, being most undoubtedly of fishes. I 

 think it is a circumstance worthy the attention of the curious, that no human 

 bones, and of birds but very few, have been hitherto found in a petrified state, 

 and belonging to the old world. 



Explanation of the plates. — Fig. 1, 2, pi. 3, are vertebrae taken from the 

 skeleton of the crocodile described by Dr. Neh. Grew, in his Catalogue of the 

 Natural Rarities at Gresham College, p. 42 and 43. 



sbcQC,, the bodies of the vertebrae ; ab of the 4th ; cf of the first vertebra of 

 the neck ; j3zt, and xy w, the spinous processes ; yP and s the ascending ; t and 

 uv the descending processes ; ghcidenpoq, the transverse, united by cartilages to 

 the bodies of the vertebrae. Grew calls them ossa mucronata. The transverse 

 processes of the 4th vertebra being lost, the roots of the mucronated processes 

 are very evident at ghik. On the under part of these vertebrae are (1 and m) pro- 



