XVII 



SYNOPSIS 



241 



First Order of the Olivine Basalts. 



Characters. — Olivine in abundance. Felspars of the groundmass 

 not in flow-arrangement. 



Formula. — Oliv., matr., cop., non-flu. 



Sub-order. 



Pyroxene 



of the 



groundmass. 



I. 



Granular 

 (gran. ) 



Prismatic 

 {prism.) 



3-. . 

 Ophitic 

 {oph.) 



Section. 



Presence or 

 absence of plagio- 

 clase phenocrysts. 



Plagioclase 



phenocrysts 



{phen.) 



No plagioclase 

 phenocrysts 

 (non-phen. ) 



5. Phen. . 



6. Non-phen. 



Genus. 



Character 



of the 



phenocrysts. 



Glassy plagioclase 



phenocrysts 



{vitr. ) 



Opaque plagioclase 



phenocrysts 



[opac. ) 



Large phenocrysts 

 of olivine and 

 pyroxene, over 

 2 mm. {magn.) 



4- 



Small phenocrysts 



of olivine and 



pyroxene under 



2 mm. Pyroxene 



scanty and often 



absent (parv. ) 



5. Vilr. . 



6. Opac. 

 7 Magn. 

 8. Parv. 



9. Vitr. . 



10. Opac. 



11. Magn. 



12. Parv. 



Species 



•I — '2 mm. 



Number of 

 specimens. 



Not repre- 

 sented. 



{Not repre- 

 sented. 



/ Not repre- 

 \ sented. 



