16 INTRODUCTION. 
of outline, indicating that the carcasses of the animals to which they belonged 
decayed upon a soft, muddy bottom of a lake or similar body of water. 
An analysis of portions of some of the bones and teeth having been made by Dr. 
Francis B. Greene, under the immediate inspection of Dr. F. A. Genth, at the re- 
quest of Dr. D. D. Owen and myself, the following results were obtained :— 
Specimen 1. Fragment of an os femoris of Titanotherium. This was compact, 
with a subconchoidal fracture, and tough. Its hardness was = 4.5; the sp. gr. = 
2.870. Lustre resinous. Color brown; opaque. On heating, it eliminated an 
ammoniacal water, together with the odor of burnt horn. 
Specimen 2. Fragment of a tibia of Archwotherium. This was compact, and 
presented an uneven, somewhat splintery, fracture. Its hardness was = 4.; the 
sp. gr. = 2.826. Lustre pearly. Color pinkish white; opaque. When heated in 
contact with the air, it assumed a green tint from the development of manganic 
acid. 
Specimen 3. Fragment of enamel from a molar tooth of Titanotheriwm. Appear- 
ance fibrous, with an uneven fracture, and very tough. Its hardness was = 4.7; 
the sp. gr. = 4.7. Lustre upon the surface subvitreous, that of the fibres pearly. 
Color bluish gray, opaque. 
Specimen 4, Fragment of dentine, from a molar tooth of Titanotherium. It was 
compact, and had an uneven, somewhat subconchoidal fracture. Its hardness was 
= 2.5; the sp. gr. = 2.935. Lustre dull. Color white, with gray spots and black 
streaks; opaque. On heating, in contact with the air, it assumed a greenish tint. 
COMPOSITION. 
Spec. 1. Spec. 2. Spec. 3. Spec. 4. 
Sesquioxide of iron. : 51) Or TACT trace trace trace 
Oxide of manganese. . . MnO trace trace trace trace 
Magnesia . 2 , 5 . MgO 0.348 1.140 0.219 0.53 
Lime : : ‘ é . CaO 49.837 47.052 51.872 49.82 
Fluoride of calcium x : 2 Call 0.716 5.086 0.099 2.90 
Baryta é : : ‘ 7. BaO 0.359 1.131 
Soda . : : : : Nao 1.134 1.572 1.288 0.75 
Potassa c j : : ~ KO 0.317 0.276 0.239 0.23 
Silica ; , : : . $10, 0.135 0.259 0.611 0.79 
Sulphuric acid. 5 ; Sw stox 1.067 2.200 1.011 AED 
Phosphoric acid. ; : » bor 34.148 32.957 39.348 36.10 
Carbonic acid i F : oy OOr 4.088 2.270 3.165 2.83 
Chlorine. 3 ; 5 FeCl trace trace trace trace 
Water : : : 5 2 HO. 2.048 1.971 0.626 2.10 
Organic matter. ; . ; : : 5.682 4.086 2.5388 2.66 
101.656 100.000 101.016 100.22 
Or, the composition may be considered thus :— 
