PLATE IV. 
DESCEIPTIONS. 
Fig. 1. 
Harzburgite. 
Slide 461. 
Magnification 6-6. 
Polarized light, 
linerals : Olivine lying in a la 
enstatite crystal. 
Sp. gr. 2-93. 
Fig. 3. 
Websterite near Lherzolite. 
Slide 476. 
Magnification 14. 
Polarized light. 
Minerals : enstatite. 
diopside. 
olivine. 
Sp. gr. 3-24. 
Fig. 2. 
Websterite. 
Slide 474. 
Magnification 14. 
Ordinary light. 
Minerals : diopside. 
enstatite. 
olivine (trace). 
Sp. gr. 3-25. 
Fig. 4. 
Norite. 
Slide 463. 
Magnification 14. 
Ordinary light. 
Minerals : rhombic pyroxene (pleochr 
basic plagioclase. 
Sp. gr. 3-03. 
Fig. 5. 
Ordinary light, 
Fig. 6. 
OUvine-enstatite-Gabbro. 
Slide 442 (same field and position). 
Magnification 14. 
Polarized light. 
Minerals : diopside. 
basic plagioclase-. 
olivine. 
enstatite (forming narrow rims 
round diopside grains). 
Sp. gr. 3-10. 
