CONTENTS. 



PART III. 



XIX. Ow the Occurrence of Agates in Dolomitic Strata of the New Red Sand- 

 stone Formation in the Mendip Hills. By the Rev. William Buckland, 

 D.D. F.G.S. F.R.S. F.L.S. {Professor of Geology and Mineralogy in 

 the University of Oxford). ........ p. 421 



XX. On the Discovery of Fossil Bones of the Iguanodon in the Iron Sand of the 

 IVealden Formatio7i in the Isle of Wight, and in the Isle of Purheck. 

 By the Rev. William Buckland, D.D. V.P.G.S. F.R.S. F.L.S. {Pro- 

 fessor of Geology and Mineralogy in the University of Oxford.) . p. 4'25 



XXI. Notice of Two Models and Sections of about Eleven Square Miles, forming 

 a part of the Mineral Basin of South Wales, iti the vicinity of Pontypool, 

 and presented to the Geological Society by Richard Cowling Taylor, 

 Esq. F.G.S. p. 433 



XXII. Some Account of the Remains of the Megatherium sent to England from 

 Buenos Ayres by Woodbine Parish, Jun. Esq. F.G.S. F.R.S. By Wil- 

 liam Clift, Esq. F.G.S. F.R.S. p. 437 



XXIII. Remarks on the Existence of the Anoplotherium and PalcBOtherium in the 



Lower Freshwater Formation at Binstead, near Ryde, in the Isle of 

 ^ Wight. By Samuel Peace Pratt, Esq. F.G.S. F.L.S. . . . p. 451 



XXIV. Observations relative to the Structure and Origin of the Diamond. By 



Sir David Brewster, K.G.H. LL.D. F.G.S. F.R.S. ... p. \'So 



XXV. Remarks on the Structure of large Mineral Masses, aiid especially on the 

 Chemical Changes produced in the Aggregation of Stratified Rocks 

 during different periods after their Deposition. Bj/ the Rev. Adam 

 Sedgwick, F.G.S. F.R.S. {Woodwardian Professor in the University of 

 Cambridge.) .......... p. 461 



XXVI. Notices and Extracts from the Minute-Book of the Geological Society, p. 487 to 498 

 1. Extract from a Letter from George Gordon, Esq. to Roderick Impey 

 Murchison, Esq. P.G.S. F.R.S., iioticing the Existence of a Blue Clay 

 on the Southern side of the Murray Firth. . . • . . p. 487 



