DESCRIPTION OF THE PLATES. 



PLATE 14. 



In illustration of the Rev. W. Conybeare's paper, on a remarkable class of 

 Organic Impressions occurring in Nodules of Flint, p. 328. 



PLATES 15 to 26. 



In illustration of Mr. William Phillips's paper on the Oxyd of Tin, p. 336. 



Plate 15. Exhibits the pi'acticable cleavages of the crystals of the oxyd of tin, 

 loading to the determination that the primitive crystal is an 

 obtuse octohedron, (Fig. 18.) p. 351. et seq. 

 Plate IG to 23. Suite of crystalline forms, representing the existing crystals 

 of this substance, with explanatory figures preceding the 

 suite of each of the 12 modifications to which the primitiv** 

 crystal is subject, p. 358. et seq. 

 Plate 24. Figures explanatory of the formation of simple and double macles, 

 and shewing that they take place in the direction of the cleavages 

 actually obtained and described by PI. 15. — p. 366. et seq. 

 Plate 25. The crystalline forms of simple and double macles, p. 368. et seq. 

 Plate 26. The crystalline forms of macles of macles, shewing that they also 

 take place in the direction of the cleavages, described by PI. 15. — 

 p. 57 i. 



PLATES 27 to 30. 



In illustration of Mr. Webster's paper on Fossil Alcyonia, p. 577. 



Phite 27, 28. Various appearances of the Tulip Alcyonium. The heads 



drawn in PI. 28, are about half the size of the originals. 

 Plate 29. Fig. 12, 13. Various sections of the same fossil, p. 381. 



Fig. 14, 15. Other species of Fossil Alcyonia. p. 386. 

 Plate 30. View of Western Lines on the south shore of the Isle of Wicht. 



where the tulip alcyonium is best observed. 



PLATES 31, 3lf, and 32, Fig. 1. 



In illustration of Dr. Mac Culloch's paper, on the Geology of various Parts 



of Scotland, p. 388. 



Plate 31. Fig. 1 & 2. Contortions in mica slate^ at Loch Lomond, p. 438. 



