144 Analyses of Books. [Feb.. 



Forty-nine of these are new species, hitherto entirely unknown to 

 naturalists. Eleven or twelve have such an entire resemblance to 

 species already known, as to leave no doubt of their identity ; and 

 the remaining sixteen or eighteen have considerable traits of re- 

 semblance to known species ; but the comparison of these has not 

 yet been made with so much precision as to remove all doubt. 

 Of the 49 new species, 27 are classed. under seven new genera; 

 while the other 22 belong to 16 genera, or sub-genera, already 

 known. Of these 7S species, 15 are animals belonging to the class 

 of oviparous quadrupeds ; while tlie remaining 63 belong to the 

 mammiferons class. Thirty-two of these last are hoofed animals, 

 not ruminant, and reducible to 10 genera; 12 are ruminant ani- 

 mals, belonging to two genera ; seven are gnawers, referable to 

 six genera; eight are carniverous quadrupeds, belonging to five 

 genera; two are toothless animals, of the sloth genus ; and two are 

 amphibious animals, of two distinct genera. 



These remains do not occur promiscuously, or huddled together 

 in the same beds. Certain animals are always found in certain 

 beds, the relative ages of wliich may be determined by their posi- 

 tion. The oviparous quadrupeds are found in more ancient strata 

 than those of the vivijjarous class. TIius the crocodiles of Honfleur 

 and of England are found beneath the chalk, and the monitors of 

 Thuringia occur in the copper-slate considered by Werner as one of 

 the oldest of the floetz formations. The great alligators, or croco- 

 diles, and the tortoises of Maastricht, are found in the chalk 

 formation. 



Tiiis earliest appearance of fossil bones seems to indicate that 

 dry land and fresh water m.ust have existed before the formation of 

 the chalk strata. But mammiferous animals occur only above tlic 

 chalk. We find the bones of the lamontin and seal in the coarse 

 shell limestone v/hich immediately covers the chalk in the neigh- 

 bourhood of Paris ; but no bones of mammiferous land animals are 

 to be found in that rock. But in the formations that cover it tliey 

 occur in great abundance. 



Hence it would appear that the oviparous quadrupeds began to 

 exist along with the fishes, and at the commencement of the pe- 

 riod which produced the secondary formations; while the land 

 quadrupeds did not appear upon the earth till long afterwards, and 

 until the coarse shell limestone had been already deposited, v;hich 

 contains the greatest [>art of our genera of shells, altiiough of quite 

 different species from those vvhich are now found in a natural state. 



The coarse shell limestone lying above the ciialk are the last 

 formed beds, which indicate a long and quiet continuance of the 

 water of the sea above our continent. Tlic beds above them con- 

 tain abundance of shells, but they are mixed with alluvial mate- 

 rials, and rather indicate violent transportations than quiet deposi- 

 tions. Where regular rocky beds appear :bove them, they ge- 

 nerally bear the marks of having been deposited from fresh water. 

 All the remains of mammiferous quadrupeds have been found cither 



