XIV INTRODUCTIOir. 



One of the difficulties of work on the Cretaceous flora is the 

 correlation of the many scattered deposits in which the plants 

 have been found. So many local names have been given to beds 

 in different places, that it is difficult to realise sometimes to 

 which period the described plants belong. Added to this is the 

 fact that, particularly in America, the relative positions of the 

 beds are still largely undecided, and individual writers use 

 terms in very different senses. 1 have not attempted exact 

 correlations, but in the accompanying table * (oj)posite) have 

 placed in series roughly in their relative positions, the principal 

 beds from which important Cretaceous plants are described. It 

 does not represent the relative thicknesses of the deposits, or, 

 indeed, the final and exact relation of the series, but has merely 

 R temporary value for the convenience of workers not specially 

 acquainted with the beds. 



It may also prove of use to give a short summary of the 

 more important work that has been done on the deposits in 

 various parts of the world, thus indicating the distribution of 

 Cretaceous plants in the various countries. Full references to 

 the papers mentioned will be found in the bibliography which 

 follows. 



AUSTRIA. 



linger (in 1867) described both Senonian and Cenomanian 

 plants from three principal localities, viz. Ischl, Sauct Wolfgang, 

 and Neue Welt. In 1871 a Schenk published a monograph on 

 the Urgonian deposits of Wernsdorf and Teschen, with notes 

 on some specimens from neighbouring localities. Schenk also 

 (1876) described eight species of Senonian plants from the 

 northern Tyrol, at Brandenberg. 



Of Bohemia, much is known owing to the work of many 

 notable palseobotanists. Corda (1846) in Iteuss, described a 

 number of Cenomanian plants from Trziblitz, Perutz and other 

 localities. The Perucer Beds have been the subject of numerous 



* NoTB. — This table is for the use of those to whotn the local names of 

 horizons are unfamiliar. It does not possess any finality, as the correla- 

 Dions vary with individual judgment. It is based partly on published 

 correJation-tables, partly on the advice of several European and American 

 geologists, and may be regarded as representing approximately the relations 

 of the principal horizons in the more important localities where Cretaceous 

 plants are found. 



