16 MantelUan Museum at Lewes, 



it would rather increase the value of the original discovery, 

 as we should have two new species of enormous reptiles 

 mstead of one. 



Among the other bones, in this museum, from Tilgate 

 Forest, there are some of one or more species of birds; it 

 ought, however, to be remarked that, as the supposed bones 

 of birds found in the lias have been discovered to belong to 

 a species of flying lizard, it may, therefore, be doubtful whether 

 these bones may not belong to a similar species of reptile. 

 Mr. Mantell, whose authority as a physiologist ought to have 

 great weight, is, however, inclined to refer these bones from 

 Tilgate Forest to birds. 



There are the remains of three species of turtles in the 

 Sussex-beds, two of which are supposed to have been fresh- 

 water species : the remains of fishes are also numerous ; they 

 consist chiefly of detached bones, teeth, and scales, no entire 

 skeleton has yet been found. 



The fresh-water formation of Sussex and part of Kent may 

 properly be named the Sussex-beds ; some of them can be 

 traced as far as Dorsetshire westward, but no distinct portion 

 of them has hitherto been discovered in the midland counties. 

 Having recently traversed these beds in various directions, I 

 intended to have ofl^ered some observations upon them in 

 the present paper, but it has already exceeded the length I 

 proposed. A very satisfactory description of the strata of 

 Tilgate Forest is given in the second volume of Mr. MantelPs 

 Illustrations of the Geology of Sussex, a work which ought 

 to be in every public library, where natural history is culti- 

 vated : the forty-two plates in the first volume, it has already 

 been mentioned, were engraved by Mrs. Mantell, without 

 whose able cooperation it would have been impossible for 

 Mr. Mantell, occupied as he is in the arduous labours of an 

 extensive medical practice, to have eff*ected so much for the 

 advancement of science. 



Besides the collection of Sussex fossils, this museum con- 

 tains many interesting organic remains from various parts of 

 the world. Mr. Mantell, with much liberality, allows the 

 museum to be seen by the public on the first and third 

 Tuesdays of every month, from one till three, application 

 having been previously made by letter. 



I am. Sir, yours, &c. 

 Hampstead, Sept. 29. 1829. Ro. Bakewell. 



P. S. The horn of the Iguanodon (e) is half the na- 

 tural size; and can only be regarded as a wart, when 

 compared with the size of the animal. The Cypris faba, 



