XVII 



SYNOPSIS 



2 \S 



First Order of the Augite-Andesites. 



Characters. — Felspar lathes or prisms of the groundmass not in 



flow-arrangement. 



FORMULA. — Aug., matr., non-flu. 



Sub-order. 



Pyroxene 



of the 



groundmass. 



I. 



Granular 

 {gran.) 



Prismatic 

 {prism.) 



3- . 

 Ophitic 



{oph.) 



Section. 



Presence or 

 absence of plagio- 

 clase phenocrysts. 



I. 



Plagioclase 



phenocrysts 



( phen. ) 



No plagioclase 



phenocrysts 



(non-phen.) 



Genus. 



5. Phen. . 



6. Non-pheu. 



Character 



of the 

 phenocrysts. 



Glassy plagioclase 



phenocrysts 



(vitr. ) 



2. 



! 



Opaque plagioclase 



phenocrysts 



(opac.) 



Large phenocrysts 

 of augite, over 

 2 mm. {magn. ) 



Small phenocrysts 

 of augite, under 

 2 mm., or none 



( pai~v. ) 



5. Vitr. . . . 



6. Opac 



7. Magn. 

 S. rarv. 



9. Vitr. 



I, 



o. Opac. . 

 n. Magn. 

 (12. Parv. 



I 



Species. 



Length of 



felspar lathes 



and prisms. 



( -02 



J ! 



I "J 



/ -02 — • 



i mm. 



2 ,, 



I '2— '3 

 I -3— '5 



— - i mm. 

 2 ,, 



I- 



•02 — "i mm. 



•I— -2 ,, 



'2— "3 ,, 



•3— '5 >. 

 •2 — *3 mm. 

 •3— *5 » 



-■3 mm. 

 •5 „ 



Number of 

 specimens. 



9 



5 



4 



6 

 4 

 3 



Not repre- 

 sented. 



Not repre- 

 sented. 



1 



j 

 4 

 7 



1 

 1 



