ENDOSKELETON. ANIMALS. 25 



MAMMALS = MAMMALIA. 



Chemical composition. 



A. 88. A small portion of fossil bone deprived of its earth. 

 0. 0. 120. Hunterian. 



A. 89. A larger portion of fossil bone, prepared in a similar 

 manner. 0. C. 121. Hunterian. 



A. 90. A portion of fossil bone from an animal belonging to the 

 genus Bos, prepared in a similar way. -0. C. 122. 



Hunterian. 



A. 91. The animal part of a portion of a Deer's horn (Cervus 

 giganteus), from Ireland, in a fossil shite. 0. C. 123. 



Messrs. Apjohn and Stokes found the animal basis to constitute 

 48-87 per cent, of the weight of the bones of the Megaceros : and 

 the following proportions of the earthy constituents : 



Phosphate of lime and magnesia . . 43'45 



Carbonate of lime U'14 



Ferric-oxide 1-02 



Silex 1-14 



Hunterian. 



A. 92. The animal part of some small portions of the cranium of 

 the Ursus spelaus or Bear of the Caverns, from Bayreuth 

 in Germany. 0. C. 124. Hunterian. 



Hunter, Phil. Trans., vol. Ixxxiv. 1794, p. 415. 



A. 93. A section of the tympanic bone of a Whalebone Whale 

 (Balceiia mysticetus), which has been subjected to the 

 action of an acid, and deprived of its earthy constituent. 

 It exhibits a concentric laminated structure and uniform 

 solidity ; the first-formed central part not having undergone 

 any change from the action of the acid, and no part ex- 

 hibiting a trace of fibres, cancelli, or vessels. 0. C. 202. 



Hunterian. 



A. 94. Another section of the same bone, similarly treated, and 

 exhibiting more distinctly the laminated texture. 0. (A 203. 



" The bony part of the organ (of hearing) is very hard and 



