246 



A NATURALIST IN THE PACIFIC 



CHAP. 



Second Order of the Augite-Andesites. 



Characters. — Felspar-lathes of the ground mass in fiow- 



arrangement. 



FORMULA. — Aug., matr.,fiu. 



Sub-order. 



Pyroxene 



of the 



groundmass. 



Section. 



4- 



Granular 



(gran. ) 



. 5- 

 Prismatic 



(prism.) 



6. 



Ophitic 

 (oph. ) 



Presence or 

 absence of plagio- 

 clase phenocrysts. 



Genus. 



Character 



of the 

 phenocrysts. 



Plagioclase 



phenocrysts 



( phen. ) 



No (or very few 



and small) 



plagioclase 



phenocrysts 



k (non-pheu.) 



I J 3- 



Glassy plagioclase 



phenocrysts 

 (vitr. ) 



Opaque phenocrysts 



of plagioclase 



(opac. ) 



15- 



Large phenocrysts 



of augite, over 



2 mm. (magii.) 



16. 



Small augite pheno- 

 crysts, under 2 mm. 

 V or none (parv.) 



Species. 



Length of 



felspar lathes 



and prisms. 



I 



•02- 

 •I- 



•2- 

 "3- 



■02- 



•1 mm. 

 •2 „ 



'5 >, 



'I mm. 



l 3" 



•1 mm. 

 •2 „ 

 '3 » 

 •5 », 



•2 mm. 



Number of 

 Specimens. 



10 



10 



4 



1 



Not repre- 

 sented. 



12 



14 

 4 

 3 



f Not repre- 

 ( sented. 

 / Not repre- 

 ( sented. 



4 



4 



f Not repre- 

 \ sented. 



f Not repre- 

 ^ sented. 



