136 CONTRIBUTIONS TO MINERALOGY. [bull. 262. 
The measured and calculated angles for all these forms are: 
No. 
Letter. 
Symbol. 
Measured. 
Calculated. 
Miller. 
0. 
p. 
4>. 
p- 
o 
/ 
o 
/ 

/ 
/ 
1 
2 
C 
a 
0001 
lOlO 

90 
00 
00 
00 
90 00 

00 

00 
3 
b 
1120 
30 
00 
90 
00 
30 
00 
90 00 
4 
h 
2130 
19 
09 
90 
00 
19 
06 
90 00 
5 
g 
3140 
13 
54 
90 
00 
13 
54 
90 00 
6 
d 
5380 
21 
34 
90 
00 
21 
47 
90 00 
7 
6 
1013 

00 
15 
23 

00 
15 20 
8 
r 
1012 

00 
22 
22 

00 
22 21 
9 
k 
3034 

00 
31 
44 

00 
31 40 
10 
X 
1011 

00 
39 
29 

00 
39 26 
11 
— 
26. 0. 26. 25 

00 
40 
26 

00 
40 32 
12 
— 
43. 0. 43. 40 

00 
41 
29 

00 
41 29 
13 
n 
11.0. TT. 10 

00 
42 
16 

00 
42 08 
14 

7076 

00 
'43 
54 

00 
43 49 
15 
8 
5054 

00 
45 
47 

00 
45 47 
16 
r 
4043 

00 
47 
37 

00 
47 38 
17 
u 
7075 

00 
49 
05 

00 
49 01 
18 
a 
3032 

00 
50 
53 

00 
50 58 
19 
P 
5053 

00 
54 
02 

00 
53 53 
20 
A 
7074 

00 
55 
13 

00 
55 12 
21 
B 
9095 

00* 
56 
09 

00 
55 57 
22 
— 
19.0. 19.10 

00 
57 
24 

00 
57 23 
23 
y 
2021 

00 
58 
42 

00 
58 42 
24 
— 
15.0.15.7 

00 
60 
25 

00 
60 25 
25 
D 
9094 

00 
61 
42 

00 
61 37 
26 
Q 
5052 

00 
63 
43 

00 
64 03 
27 
E 
8083 

00 
65 
30 

00 
65 29 
28 
F 
11.0. IT. 4 

00 
66 
10 

00 
66 09 
29 
3031 

00 
67 
52 

00 
67 56 
30 
G 
10.0:10.3 

00 
69 
53 

00 
69 57 
31 
H 
7072 

00 
70 
57 

00 
70 50 
32 
K 
11.0. TT. 3 

00 
71 
38 

00 
71 39 
33 
Tl 
4041 

00 
73 
04 

00 
73 05 
34 
L 
10. 0. To. 1 

00 
83 
09 

00 
83 04 
35 
s 
1121 
30 
15 
54 
40 
30 
00 
54 55 
36 
v 
1122 
29 
54 
35 
22 
30 
00 
35 27 
37 
i 
2131 
19 
02 
65 
11 
19 
06 
65 19 
38 
? 
4154 
10 
56 
41 
49 
10 
53 
43 17 
39 
1 
3252 
20 
38 
60 
03 
23 
25 
60 50 
