242 



A NATURALIST IN THE PACIFIC 



CHAP» 



Second Order of the Olivine-Basalts. 



Characters. — Olivine in abundance. Felspars of the groundmass 

 in flow-arrangement 



Formula. — Oliv.^ matr., cop., flu. 



Sub-order. 



Pyroxene 



of the 



groundmass. 



4- 



Granular 



(gran. ) 



Prismatic 

 {prism.) 



6. 



Ophitic 

 {oph.) 



Section. 



Presence or 

 absence of plagio- 

 clase phenocrysts. 



7- 



Plagioclase 



phenocrysts 



(phen.) 



No plagioclase 

 phenocrysts 

 (non-phen. ) 



9. Phen. . . 

 ID. Non-phen. . 



11. Phen. . . 



12. Non-phen. . 



Genus. 



Character 



of the 



phenocrysts. 



13- 



Glassy plagioclase 



phenocrysts 



{vih'. ) 



14. 



Opaque plagioclase 



phenocrysts 



{opac. ) 



15- 



Large phenocrysts 



of olivine and 



pyroxene, over 



2 mm. [magn.) 



16. 



Small phenocrysts 



of olivine and 



pyroxene, under 



2 mm. Pyroxene 



scanty and often 



absent (parv.) 



17. Vitr. 



18. Opac 



19. Magn. . . . 



20. Parv 



21. Vitr 



22. Opac 



23. Magn 



24. Parv 



Species. 



Length 



of felspar 



lathes. 



Number of 

 specimens. 



Not repre- 

 sented. 



Not repre- 

 sented. 



