INTRODUCTION. 25 



A portion of the matrix attached to the bones of the Titanofherium, obtained 

 from the lowest bed of the geological section, No. 10, p. 13, also analyzed by Dr. 

 Owen, was found to be composed as follows: — ^ 



Water HO 4.00 



Silica • . . . . SiOs 69.00 



Lime CaO 10.00 



Carbonic acid CO3 12.20 



Sesquioxide of iron ......... Fe^Oj 7.20 



Alumina "... Al^Oj 4.20 



Phosphoric acid .......... 1.90 



Chlorine CI 0.037 



Sulphuric acid SO3 0.03 



Alkalies and loss . 1.433 



100.000 



The bones, unlike those of the gypsum quarries of Montmartre,-' (which are 

 of the same age but not mineralized) are as completely petrified as any found in 

 the most favorable circumstances. Most usually they are exceedingly hard, com- 

 pact, and heavy, and only rarely have they become friable. The cellular, vascular, 

 and medullary cavities are filled with mineral matter, in most instances, consist- 

 ing of crystallized or amorphous silex or chalcedony, which is sometimes botryoidal 

 in its arrangement in the larger cavities. 



The bones are preserved in very various degrees of integrity, some being beau- 

 tifully perfect, whilst others are crushed or otherwise fractured, the crevices being 

 filled with the ordinary matrix, or with a harder mineral matter. The latter 

 evidently were subjected to violence while enveloped in a soft mud which now 

 constitutes the matrix; for in most instances in which the fragments have been 

 widely separated, they still retain their proper relative position to one another. 



The teeth, where they exist, are usually preserved quite perfect, and in all cases 

 their pulp cavities are filled with dense amoi-phous, or with crystallized silex. 



The dentine is commonly of a cream color, or pure white, but occasionally it is 

 tinged with a roseate hue ; and in most cases where exposed from the enamel having 

 been worn off, it is covered by a lamina of compact peroxide of iron. Its texture is 

 firm, though more friable than in the recent condition. The enamel is well pre- 

 served in texture, but in every instance is stained. Its color passes from trans- 

 lucent light brown resembling horn, through difierent shades of brown, to black 

 with a brown or bluish tinge. Its surface is highly lustrous, and in those cases in 

 which it is dark in color, resembles polished steel. 



The bones are cream white, yellowish, brownish, brown, and iron gray, and 

 most frequently have a slightly polished surface. Very often a thin layer of 

 brown oxide of iron adheres to the latter, and is difficult to detach, without re- 

 moving a portion of the osseous structure. 



None of the specimens have the appearance of being water worn, or rolled, but 

 all the teeth and processes of bone, when entire, exhibit all their original sharpness 



' Eep. of a Geolog. Surv. etc, p. 606. 



