950 THE JOURNAL OF GEOLOGY. 
banakite, under the name of guarts-banakite, the amount of quartz 
however being very small. 
The two rocks analyzed are closely alike in alkalies and lime, but 
the first one is lower in silica and slightly higher in alumina, iron 
oxide and magnesia. They differ somewhat in mineral composi- 
tion, though both are characterized by abundant feldspar and 
biotite. 
The first one (analysis 6) is a gray rock, distinctly crystalline 
with a few megascopic crystals of feldspar and mica. It is holo- 
crystalline, and is composed of lath-shaped, rectangular and allo- 
triomorphic feldspars, with considerable brown biotite, besides 
magnetite and a little augite, partly decomposed. There is a very 
little quartz and calcite. The central portion of the crystals of 
feldspar is lime-soda-feldspar, in some cases labradorite. The 
marginal portion is orthoclase which forms a considerable part 
of the crystal, but is subordinate in amount to the plagioclase. 
The second rock (analysis 7) is light-gray with numerous 
small tabular feldspars and some large ones, besides a few 
phenocrysts of biotite. The rock is holocrystalline and nearly 
panidiomorphic, the feldspars of the groundmass being in small, 
rectangular to lath-shaped crystals with fluidal arrangement. The 
groundmass also contains a small amount of biotite, very little 
magnetite and augite, and some colorless apatite. The feldspar 
phenocrysts are labradorite, while the feldspar of the ground- 
mass is mainly orthoclase with kernels of fresh feldspar that has 
the optical characters of oligoclase. There is very little quartz 
and a little chlorite or serpentine. 
The mineralogical analogy between banakite and shoshonite 
is chiefly in the association of phenocrysts of labradorite with 
microlites of orthoclase. Biotite and augite occur in some rocks. 
of both classes, while olivine is present in one variety of bana- 
kite, and is common to most shoshonites. These banakites are 
not properly minettes on account of the prominence of labrador- 
ite, and they differ from kersantites by the presence of ortho- 
clase in the groundmass. They bear the same relation to’ 
kersantite that shoshonite bears to normal basalt. They are the 
