252 GEOLOGY. 



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Bohnerz. — In southwestern Germany, and in parts of France and 

 Switzerland, there are peculiar and interesting mineral-spring deposits 

 (Bohnerz formation) yielding abundant fossils. This formation occurs 

 mainly near the outcrops of the White Jura. The mineral matter de- 

 posited from the springs incased many bones of mammalia, as well as 

 the bodies of other animals. On the decay of the organic matter, per- 

 fect molds of their forms were preserved. By being properly filled, 

 excellent casts even of delicate parts of flowers and insects are some- 

 times obtained. The name Bohnerz refers to bean-like concretions of 

 iron ore. 



Other continents. — On other continents, the Oligocene has not been 

 generally differentiated. It is known in northern Africa, a part of the 

 Mediterranean province, and perhaps in Soudan. 1 It is known in Pata- 

 gonia, where it is partly marine 2 and partly non-marine, and it may 

 be widely distributed outside of Patagonia. The Oligocene of the An- 

 tillean and Central American regions has already been referred to. In 

 Panama, nummulitic limestone occurs. 3 In New Zealand, igneous rock 

 is associated with the sedimentary beds of this epoch. 



The Life of the Oligocene. 



The vegetation. — The mixed evergreen and deciduous forests of the 

 Eocene merged into very similar ones in the Oligocene, particularly in 

 Europe. There palms continued to be abundant and varied, growing 

 even in north Germany, and being richly displayed in southern France 

 and northern Italy, especially in Liguria. They seem to have become 

 rare, however, in the United States, for in the Florissant sediments, 

 which are rich ir plant fossils as well as insects, palms are barely repre- 

 sented. The Florissant fossils imply a return to a diversified angio- 

 sperm flora. Of 160 species identified by Lesquereux, 133 were angio- 

 sperms against 8 conifers, while 19 belonged to lower orders. The 

 conifers were represented by pines, yews, and sequoias which closely 

 resembled those of Europe, where they were relatively more abundant. 

 The variety of the angiosperms was great, and widely distributed 



1 De Lapparent, La Geographie, Vol. XI, p. 1. 



2 Hatcher. See references to this region under Eocene, and especially Geol. Mag., 

 1902, p. 136. 



3 Bertrand and Zurcher, Etude G6ologique sur l'lsthme de Panama (Rev. in Geol. 

 Mag., 1903, p. 419). 



