114 ~=Brush and Dana—Danburite from Russell, N. Y. 
casional exception of hry domes d and w, uniformly unpolished 
and They show, moreover, many par- 
tially developed laine which do not admit of determination. 
In these latter respects they resemble crystals of other species 
found in a similar situation (e. g. pyroxene in ee. The 
determination of the symbols of the various planes was accom- 
plished without difficulty with the aid of the zonal  delationt 
Fig. 5. Fig. 6. Fig. 7. 
and with 2 Sie Tag angles, but only re few exact measure- 
ments were possib hp rismatic ae T and /, are, how- 
a nape commo ay tlh and highly polished. As fund- 
angles* the following, as the mean of many single 
mse Ras i were accepted : 
LAR 110,110 = 57° 4754" 
a 101.101 = 82°53’18" 
From these the following nea ratio is obtained = — 
c pene 
1: aa6t 1-000 
The prac ty sieves are, as follows:— 
0 001 8 3-3 321 
a ia 100 
b ix 010 0 1 111 
e 2 221 
k i} 320 
I 110 u $2 124 
m if 230 v 1-2 122 
1 4-2 120 r 2-3 121 
n 4 140 
* The angles given are all the supplement angles. 
