248 



A NATURALIST IN THE PACIFIC 



CHAP. 



Second Order of the Hypersthene-Augite Andesites. 



Characters. — Felspar-lathes in flow-arrangement. 



Formula. — Hypersth.-aug., matr., flu. 



Sub-order. 



Pyroxene 



of the 



groundmass. 



Section. 



Genus. 



4- 



Granular 

 (gran. ) 



Presence or 

 absence of plagio- 

 clase phenocrysts. 



Plagioclase 



phenocrysts 



(pken.) 



8. 



No plagioclase 



phenocrysts 



(non-pheu.) 



Character 



of the 



phenocrysts. 



Species. 



. 5- 



Prismatic 



(prism. ) 



6. 



Ophitic 



(oph.) 



(* 



Pken. 



Glassy plagioclase 



phenocrysts 



(vitr. ) 



14. 



Opaque phenocrysts 



of plagioclase 



(opac.) 



15- 

 Large phenocrysts 



of pyroxene, 

 over 2 mm. (i/iagn.) 



16. 



Small pyroxene 



phenocrysts, under 



2 mm., or none 



(parv. ) 



Length 



of felspar 



lathes. 



Number of 

 specimens. 



I 02 — • 



1 mm. 



2 ,, 



10. Non-phen. 



f Not repre- 

 \. sented. 



f Not repre- 

 \ sented. 



Not repre- 

 sented. 



Not repre- 

 sented. 



4 

 2 



Not repre- 

 sented. 



Third Order of the Hypersthene-Augite Andesites. 



Characters. — Felspars of the groundmass short and stout 



(orthophyric). 

 Formula. — Hypersth.-aug., matr., orth. 

 Remarks. — The same classification is to be employed here as in 

 the case of the two previous orders, but as the rocks in my collec- 

 tion that belong to this order are not numerous (nine sections), it 

 will be sufficient to refer to the general remarks on the order 

 on p. 290. 



