

; 



OF ASCENSION. 



*»; 



153 



s 



tain white crystals of quartz and minute, brown, acicular 

 transparent crystals of augite (diopside). ' ' ' 





) 



Upper 

 Gallery. 



Wall-case 2. 









; : 



rf«s 



47— Light grey trachyte, with layers of pitchstone, in 

 contact with and passing into paler earthy trachyte, with 

 included fragments of pearlstone. 



48. Reddish-brown augitic lava, with crystals of glassy 



'spar. v y 



49.-- Laminated traciiytic lava, with crystals of glassy 



fi 



felspa 



50. 



• •■ w. 



•V 



fi 



I 





and composed of alternate layers of augitic and felspathic 



Brick-red trachyte, with decomposing crystals of 



lavas. 

 51. 



. _■ glassy felsp 



52. 



augitic LAVA, with crystals of glassy felspa 

 crystals of specular iron on one side of the specimen. 



53. 



and a feAv brown stains. 



glassy felspar 





54. 



d 



tt 



glassy f 



55. 



quartz. 

 56. 



Trachyte, in a decomposing state, with crystals of 



elspar. 



•Trachyte, partially coated with a thin deposit of 

 Reddish-brown augitic lava, with numerous crys- 



■'< 



s syf 



4 



57. 



crystals of gypsum. 



53. 



(another variety) 



one side with 





I- 





Slightly cellular greyish augitic lava, with numer- 

 — « C il.defined crystals of glassy felspar. 



n j^'~Z r 7 liAmY ' n0 r0RPIIY RY, composed of crystals of 

 giassyjelspar, with brown spots in a light brown tracl ' ' 

 oase and forming veins of hard compact trachyte in 



earthy trachytes. * 



Cellular porphyry, with opaque white crystals 



the 



60. 





of 



cr ystals of analcime. 

 trachyte. 



fels 



Some of the cells contain minute hair-like 



Found embedded in the earthy 



