132 
ON THE GEOLOGY AND NATURAL HISTORY 
MINERALS AND GEOLOGICAL SPECIMENS, continued. 
13. Mica slate, ...... 
Laramie hills. 
50. Metamorphic limestone, similar to No. 48, Rawhide butte. 
14. Hornblende rock in granite, 
do. 
51. Talcose slate, . 
. do. 
15. Red felspar from No. 14, ... 
do. 
52. Felspathic granite, flesh-colored, 
do. 
16. Crystalline quartz from No. 14, 
do. 
53. Mica slate, with garnets, . 
. do. 
17. Flesh-colored felspar from No. 14, 
do. 
54. do. very fine-grained. 
. do. 
18. Mica slate, with garnets, .... 
do. 
55. Talcose slate, dark, . 
. do. 
19. Mica slate, with garnets, .... 
do. 
56. do. light, . 
. do. 
20. Mica, containing iron, .... 
do. 
57. Porphyritic trap, 
. Black hills. 
21. Flesh-colored felspar in large crystals, 
do. 
58. Hornblende slate, 
. do. 
22. Chlorite slate, ...... 
do. 
59. Felspathic granite, pink, . 
. do. 
23. Mica slate,. 
do. 
60. Plates of mica from No. 59, 
. do. 
24. Granite, coarse, over No. 23, . 
do. 
61. Quartz vein in chlorite slate, 
. do. 
25. Felspathic granite, pink, 
do. 
62. Chlorite slate, . 
. do. 
26. Quartz veins in No. 25, .... 
do. 
63. Trachyte, 
do. 
27. Hornblende rock, masses in granite, 
do. 
64. Quartz veins in No. 63, . 
. do. 
28. Granite, fine-grained, .... 
do. 
65. do. 
. do. 
29. Hornblende rock, ..... 
do. 
66. Chlorite slate, . 
j Rawhide butte, 
• 1 W. side. 
30. Hornblendic granite, .... 
do. 
67. Hornblende rock, underlying 
Tertiary, 
do. 
.31. Hornblende, with crystals of felspar, 
do. 
68. Schorl in quartz from clay slate, 
. Black hills. 
32. Mica slate, hornblendic, .... 
do. 
69. do. do. 
. do. 
33. Mica slate, hornblendic, .... 
do. 
70. Augite, .... 
. do. 
34. Mica slate, with large plates of mica, 
do. 
71. Quartz, with felspar, 
. Laramie hills. 
35. Granite, white felspathic, .... 
do. 
72. Porphyritic trap, columnar, 
f Stone butte, 
{ Black hills 
36. Quartz, veins in No. 35, .... 
do. 
73. do. do. 
. do. do. 
37. Silieious limestone, Silurian or Devonian,. 
do. 
74. do. do. 
. do. do. 
38. do. highly crystalline, . 
do. 
75. Trachyte, 
. do. do. 
39. do. do. 
do. 
76. Vesicular trap, 
. do. do. 
39J. Syenite, pink, under No. 39, 
do. 
77. Trachyte, 
. do. do. 
40. Metamorphic silieious limestone, 
Rawhide butte. 
78. Silieious limestone, . 
. Rawhide butte. 
41. do. do. purplish, . 
do. 
79- Porphyritic trachyte, 
| Stone butte, 
{ Black hills 
42. Quartz, in granite, . . . . . 
do. 
80. Compact trachyte, with scales of mica, 
. Bear peak, do. 
43. Metamorphic limestone, gray, . 
do. 
81. do. do. 
do. 
. do. do. 
44. Mica slate, ...... 
do. 
82. Gray basaltic trap, . 
. do. do. 
45. Micaceous granite, . . . . . 
do. 
83. Porphyritic trachyte, 
. do. do. 
46. do. . 
do. 
84. do. 
. do. do. 
47. Mica slate, fine-grained, . 
do. 
85. Quartzite, 
. do. do. 
48. Metamorphic limestone, crystalline, . 
do. 
86. Gray trachyte, . 
. do. do. 
49. do. purplish, 
do. 
87. Metamorphic sandstone, . 
. do. do. 
II. SEDIMENTARY ROCKS. 
Silurian and Devonian. 
89. Potsdam sandstone, red, with Lingula aniiqua Bear peak. 
90. do. gray, fine, with Obolus, do. 
91. do. porous, with Trilobites, do. 
92. Metamorphic, conglomerate over granite,. Laramie hills. 
93. do. with cherty pebbles, . . do. 
94. do. do. . . do. 
95. Argillaceous limestone, Devonian, . . Laramie hills. 
96. Metamorphic conglomerate, . . . do. 
Carboniferous. 
97. Limestone, with spirifer, .... Black hills. 
98. B1 ue cherty limestone, with Athyrissubtilita, do. 
99. do. with corals, . . do. 
