404 NATURAL HISTORY. 



SECOND ORDER. 

 TERTIARY ROCK FORMATION. 



The Tertiary or Third Formation was deposited 

 after the secondary, and may be considered as being 

 made up of the disintegration of the two foregoing 

 series, namely, by silicious limestone or fresh water 

 chalk, together with sand, clay, and marl. The tertiary 

 strata contain a great number of fossil remains analogous 

 to or identical with species still existing, and also gigan- 

 tic specimens of a race of quadrupeds long since extinct. 

 Fossil shells, fragments of wood, the remnants of primi- 

 tive forests overthrown by volcanic agency the latter 

 often found embedded in the Brown Coal Measures 

 bones of fishes, crocodiles and other reptiles, of birds and 

 even of quadrupeds, such as apes, hyenas, bears, etc., 

 the latter being isolated and often entire. The mention 

 of these remains of animals belonging to genera still 

 existing but the species of which is now lost, induces, in 

 this place a consideration of 



The Bone Caverns found partially in this formation 

 and partially in the earlier formations, remarkable for 

 the number and variety of bones they contain of ani- 

 mals mostly of races belonging to the earliest times ; 

 they appear to have been destroyed in the geological 

 revolution which upheaved the Alps and gave its present 

 form to Europe. These caverns seem to have afforded a 

 resting-place to many varieties of animals that frequented 

 them as suitable spots for devouring their prey, or finally 

 came to them to die. Deer, horses, oxen, hyenas, wolves, 

 dogs, etc., all seem to have congregated in those subter- 

 ranean abodes ; can it be assumed that they dwelt in 



