290 Geology of 



it occurs in flattened stems, some of large dimensions, the interior 

 being filled with flint, woodopal or woodstone, and the bark alone 

 preserving the woody structure, thus suggesting that these trees either 

 belonged to the Acrogens or Endogens division. A few stems of trees 

 have also been obtained exhibiting the woody structure throughout, but 

 they have not as yet been microscopically examined, to settle whether 

 they are the remnants of eoniferas or of dicotyledonous trees. Several of 

 the most characteristic sections, both from the Malvern Hills and the 

 Mount Somers district, illustrating the relation of the melaphyres and 

 quartziferous porphyries to each other, and to the palaeozoic rocks 

 underlying them, have been added on plate Xo. 3. 



The following analyses were made in the Laboratory of the Imperial 

 Geological State Iustitute of Vienna by Carl Ritter von Hauer : — 



White Quartziferous Porphyry with Garnets. — Mount Misery, 

 Malvern Hills. 



Silica ... ... ... ... 73-31 



Alumina ... ... ... ... 11-00 



Protoxyde of iron ... ... ... 1'55 



Lime * ... ... ... ... 5'32 



Potash ... ... ... ... 4-70 



Soda ... ... ... ... 2-44 



Water ... ... ... .„ 030 







98.62 



"With traces of protoxyde of Manganese. 





Green Quartziferous Porphyry. — Snowy Peak, Malvern Hills 



Silica 





7600 



Alumina 





7-16 



Protoxyde of iron 





500 



Magnesia 





376 



Potash 





530 



Soda 





222 



Water 





0-66 



10010 



