Ill 



\ 





YOLCANIC ROCKS FROM ADEN. 



131 



102 to 121, from various localities chiefly in Transyl- 

 vania, are illustrative of the greenstones (102 to 104), the 

 porphyries (105 to 107), and the trachytes of that country. 



On the lower shelf is a series of specimens (122 to 130) 



from the extinct tertiary volcanos of the Eifel. 



131 to 137 are principally varieties of highly crystalline 



Upper 

 Galleky. 



Wall-case 1 



Vincent. 



from the volcanic mountain of 



Corsica. 



greenstone ft 



Specimens of lava, pumice, sulphur, &c. (140 to 147) 

 from the Peak of Teneriffe, are placed on the upper shelf, 

 together with (139) a specimen of stalactitic lava from 

 Etna, which is too large to accompany the collection to 

 which it more properly belongs H. W. Bristow. 



Wall-case l. 



Volcanic Rocks and Minerals from Aden. 



* 



Presented by the Honourable the Court of Directors of the 



East India Company. 



The Peninsula of Aden, near the entrance to the Red Sea, 

 is a promontory about 5^ miles long by 2\ to 3^ miles broad. 

 It is formed of a mass of dark, sombre-looking rocks, which 

 attain an elevation of 1776 feet above the sea level. The 

 town of Aden is built on the eastern side of the promontory, 

 in a plain, surrounded by an amphitheatre of rocky moun- 

 tains. This plain, which is nearly flat, and but slightly 

 raised above the level of the sea, is three miles in cir- 

 cumference, and apparently the crater of an extinct 

 volcano.— H. W. B. 



L — Basalt traversing the volcanic rocks in dyke% 

 2 — Grey massive basalt, very slightly vesicular, and 

 With a few small crystals of glassy felspar. 



e 2 



n 



