338 The American Geologist. June, 1904. 
There is a small amount of nepheline present ; it is a clear 
mineral with no relief and with a low interference color in thin 
sections. These crystals have a prismatic shape, parallel ex- 
tinction, and an average length of .1 mm. and an average width 
of .05 mm. 
Calcite, serpentine and chlorite are present as weathering 
products, and needles of apatite can be detected in the ground 
mass. 
Camptonytes v.ere found in the Josie mine near the Josie 
dike at the 600 foot level. The specimens from this dike 
showed olivine in large crystals, most of which is changed to 
serpentine. The rock also contains more biotite than in the 
preceding dike. 
At the 700 foot level of the War Eagle mine is a dike of 
camptonyte, Fig. 3, (105, 106 and 108 Rossland) ; its composi- 
tion is much the same as that of the preceding rock, but the 
groundmass is decidedly porphyritic and the crystals of au- 
gite and of plagioclase are much larger. The groundmass is 
composed of plagioclase, augite, hornblende, biotite, nepheline 
and magnetite. 
Another dike of camptonyte. Fig 4, (100 and 103 Ross- 
land J was found at the 700 foot and 900 foot levels of the War 
Eagle mine near the new shaft. This is a ten-foot dike and 
differs from the smaller dike last described in the War Eagle 
mine in being of darker color, and finer grain. It contains more 
hornblende than the preceding and most of this is primary. 
Very little diopside is noted, and the feldspars and biotites are 
smaller. No nepheline was found. 
Augite Camptonyte. — At the 700 foot level of the Le Roi 
mine is a 40- foot dike (9 Rossland) which differs from the 
preceding type in having the monoclinic pyroxene predominant 
over the hornblende. 
In thin sections. Fig. 5, the rock shows lamprophyric struc- 
ture with phenocrysts of pyroxene in a ground mass composed 
largely of augite, feldspar, biotite, apatite, hornblende, and 
magnetite, and weathering products as calcite and chlorite. 
The predominant mineral, augite, is brownish in color and ap- 
pears in two generations ; those of the first generation occur 
only as phenocrysts, are somewhat weathered and contain in- 
clusions ; they show a light brown color with slight pleochroism 
