202 



LOWER MIOCENE STRATA. 



[Ch. X. 



the arctic latitudes of the northern hemisphere, we find in 



surturbrand in Iceland, recently 

 an assemblage of fossil plants 



certain beds 



of lignite or 



Heer 



resembling in many respects that of GEninghen, before men- 

 tioned, which, though not of so sub-tropical a character ex- 



much 



temp 



surpass that of the vegetation now proper to the same region.* 

 Lower Miocene strata. — By referring to our table at p. 139 

 the reader will see that the Lower Miocene strata come next 

 in order as we recede from the more modern formations to 

 those of higher antiquity. They contain scarcely any livin 

 species of shells or plants, yet so many of their fossil remains 

 are common to them and the Upper Miocene formation, that 

 this fact alone would lead us to expect that they would afford 



climate. Such an anticipation is more 

 than confirmed, both by negative and positive evidence ; for, 

 in the first place, nearly all the genera of plants which in 



m 



(E 



ower Miocene, while 

 Among these last are 



perate latitudes, are wanting in the 

 the tropical forms are more numerous, 

 palms of the genus Phoenicites, closely allied to the date- 

 palm. About 80 other plants are enumerated by Heer, all of 

 which would be cut off by such a winter as now prevails in 

 Central and Southern Europe. Ligneous plants constitute 

 two-thirds of the flora, and the preponderance of evergreens 

 exceeds even that observed in the Upper Miocene strata of 



(Eninghen. There are also more reptiles in these older beds, 

 and 



some 



size. 



Among them are no less 



than three crocodiles and fifteen land and freshwater tor- 



t The Lower Mioce 



from 



Italy northwards to Devonshire, and even to Iceland. In 

 these high latitudes, however, the tropical and sub-tropical 

 genera disappear, though the vine and tulip-tree and some 



othei 



o 



temperature 1 

 g to the same 



Eahr. warmer 



+ 



* Heer and Gaudin, Climat du Pays $ Heer and Gaudin, Climat du Pays 



Tertiaire, p. 178. Tertiaire, pp. 174, 207. 



t Heer, Urwelt der Schweiz, p. 401. 



1 



\ 





U 



- 



pro 



: 



A 













Lr # 





ad, ' 

 safes, 



\ 



r 



.« i 



A 



. 







■ 



;0Si] 



- 



til] 



> 



. 





•> 







I ! - them 

 f 



>, 1 





•*i 



V 





- 



1 





'l 







-, 





H 



* 



