The Iguanodon in the sands of the chalk. 357 



Two iinguical or claw-bones, somewhat of a flattened form, and 

 resembling those of a land tortoise. The largest is four inches in 

 length, and two and a half inches wide at the base. 



Fragments of large flat bones, which may probably belong to the 

 pelvis. 



V^ertebraj both caudal and lumbar ; these are of the usual fossil 

 saurian type, having both faces slightly depressed. The largest 

 vertebras are very greatly flattened by compression. 



Numerous portions of ribs ; one possesses a double termination 

 like that of the fifth rib of the crocodile. 



A portion of one tooth, and the impression of another, decidedly 

 of the Iguanodon. 



One bone, twenty eight inches long, similar to that figured on the 

 clavicle of the Iguanodon, in the Geology of the south-east of 

 England, Plate IV. figs. 1 , 2 ; a portion of another bone of the same 

 kind is also partially exposed. 



With the exception of the unguical bones, all those above enume- 

 rated resemble those of the Iguanodon, which have been dug up in 

 Tilgate Forest ; and the circumstance of the teeth being imbedded 

 with the bones, serves to confirm the inferences that have been dedu- 

 ced from the previous discoveries of detached portions of the skele- 

 ton. It is not a little remarkable that no traces of the jaws of the 

 Iguanodon have been observed ; sooner or later, however, as M. 

 Cuvier remarked in a letter to Mr. Mantell, "il est impossible qu'on 

 ne trouve pas un jour, une partie du squellette reunie a des portions 

 de machoires portant des dents." 



Mr. Mantell estimates the probable length of the individual whose 

 remains are above described, at about seventy five feet. 



POSTSCRIPT. 



To THE EDITOR. — Dear Sir — As none of the specimens are figured 

 to which I alluded in my late communications, I enclose a few sketch- 

 es in outline. The caudal vertebrae, briefly described in Geol. Suss. 

 p. 333, are probably of the Hylaeosaurus, you will at once be struck 

 with the enormous height and size of the spinous processes, and 



