BY H. I. JENSEN. 597 



which has the habit of sanidine but is probably anorthoclase. 

 The aegiriiie is highly pleochroic in colours ranging from grass- 

 green to bluish-green. It has straight extinction, and compen- 

 sates in the direction of the length of the needles. It occurs in 

 bundles of acicular crystals, and commenced to crystallise early, 

 being sometimes enclosed in felspar phenocrysts; and finished 

 late, sometimes being seen enveloping arfvedsonite [cj). Note on 

 p.594). The arfvedsonite occurs in characteristic moss-shaped 

 aggregates which crystallised simultaneously with the felspar of 

 the base. The pseudoleucite and nosean occur in the form of 

 idiomorphic phenocrysts giving square, hexagonal, and polygonal 

 sections, but rarely showing cleavage. Some of the crystals are 

 clear, but most are dusty from an abundance of inclusions, in 

 addition there are irregular patches of an isotropic mineral which 

 is sometimes clear and sometimes yellowish from zeolitic decom- 

 position-products. This mineral is frequently seen in the 

 intervals between needles of felspar arranged in radiating, 

 pseudospherulitic manner. Probably it is analcite. The decom- 

 position-products are kaolin, zeolites, and ferrite. 



4. Order of consolidation : 



i. Phenocrysts of Albite 



ii. ^girine 



iii, Nosean 



iv. Anorthoclase 



v. Arfvedsonite 



vi. Katophorite (1) 



vii. Augite Acmite 



viii. Analcite (?) 



5. Name : Trachytic Nosean-Analcite-Phonolite. Magmatic 

 name, Nordmarkose (see Analysis W.222). 



6. Chemical Notes : all the patches referred to the felspathoid 

 group of minerals gelatinise with acids and take stains strongly. 



W.220. Loc: Mount Bingy Grumble. 



1. Handspecimen dark brownish with greasy lustre; porphyritie 

 in phaneric phenocrysts. 



