of Mineral Species of the Trimetric System. AT 
respond to the dimensions given in the table. Should 
we change it, and make the brachydiagonal the ver- 
tical axis, then: 
T= 93° 52’, 15 ==. 91°.29', 13. 95° 2, 
And, again, if we make the macrodiagonal the 
vertical axis : 
I= 91° 29, 13 84 59, N= SO 8’. 
The symbols of these planes in these three posi- 
tions (which we may call A, B, C,) are as follows : 
A (figure) 1 6 Bae lag 
B 1 } 

tt 
C be ADA aca 4t =O (base) 
The form is near that of Bournonite. It is also related distantly to 
the Columbite species, the prominent difference being five degrees in 
the angle of the vertical prism 
The species of Table II. fall into four sections, depending on 
the angles of the unit domes. 




TABLE IL 
Angle of the Vertical Prism I near 102°. 
Pris Dome Dome Axes 
L li. Ji. GLP se: 
aes 
re Re ~ (4) 103° 30’ 58° 17’ 70° 321-7934 : 1 : 1°2683 
Spar, - 01° 40’ 63° 40’ 74° 361-6107 : 1: 122976 
- - -| 108988 62°49’) 75° 29/11-6415:1:1-2715 
-| 108° 16’) 60°20 72° 3411-7205 : 1 : 12632 
: 04° 2’) 62° 389"| 75° 5211-6439: 1 : 12807 
-| 102° 56) 61° 25" 72° 3811-6836 : 1: 12557 
- | 101° $27(2z) 64° 7/\(2%) 74° 58’11-5967 : 1: 12247 
-| 107° 40/) 65° 52] «88° 611-5437: 1 : 18680 

2 7° 40 74° 20'11-4919 : 1: 1°1810 
- | 101° 58/32). 65° 18'\(9x) 76° 40/1-5606 : 1: 12342 
: « — {(1z) 46° 16’\(1%) 65° 86//2-3408 : 1: 12342 

-} 100° 404, 78° 83° 30'1-3511 : 1: 12059) . 
98° 6’) 75°40’) — 83° 40'/1-2876 : 1: 11526 
100° 32 2/| 94° 24/l1-3962 : 1: 1-208 
- (4) 100° 58/42) 70° 50’\(4x) 81° 80/{1-4063 : 1: 12121 
ye de le 87° 14//1-3514 : 1: 12853 
’ ' ‘ ' ' 












eke 99° 56/)(27) 89° 45’) = 99° 4111-0044: 1 
- - -={ 100° 40% 86° 45 97° 28/\1-0684 : 1: 12059 
rae eee, heel 99° 13/11-0387 : 1: 1°2149 
-~ - =] 100° 28/ © 6411-0463: 1: 1 
- - =} 100° 93° 16/]1°1260 : 1: 11918 
Se is gg? 2" 92° 431-0977 : 1: 11151 
-- 01° 97° 40/1-0607 : 1 : 12131 
- + Cao 122° 5006455 : 1: 11847 
~ - +} 108° 54’ | 128° 2606170 : 1: 1-2776 
_ = 0° 118° 32"; 126° 58 5 1918 
- - «| 104° 107(22)114° 29’| 126° 417106434 : 1: 1:2838 
+ Maes 99° 46’), 118° 28’) 126° 44705953 : 1 : 11868 
tos] 1029 86" @ +1: 12482 
arsine ae 101° 20’ a :1:1-2208 



