184 The Upper Cretaceous Floras of the World 



Continental geologists usually consider the Albian as the uppermost stage 



of the Lower Cretaceous and this was the usage followed by the writer in 



the Maryland Geological Survey volume on the Lower Cretaceous. The 



upper limit of the Cretaceous is involved in the so-called Laramie problem 



of American geology and in the discussions of the age of the etage 



Montian of the European section. Since all of the Maryland floras and 



faunas are considerably older, the question of the Cretaceous-Eocene 



boundary does not concern the present discussion. 



The Upper Cretaceous sediments of Europe were early differentiated 



into the following four lithologic units: (1) Craie glauconieuse or 



gres vert superieur, (2) craie marneuse, (3) craie blanche, (4) calcaire 



pisolithique. These four divisions were named : 



Cenomanian, d'Orbigny, 1843 (from Mans, Sarthe). 



Turonian, d'Orbigny, 1843 (from Touraine). 



Senonian, d'Orbigny, 1843 (from Sens, Yonne). 



Danian, Desor, 1850 (from the extensive development of the 



calcaire pisolithique in Denmark), equivalent of Garum- 



nian, de Leymerie, 1862 (from Garonne). 



These terms of d'Orbigny are still widely used, the only material modifi- 

 cation being the recognition of the greater importance of the Senonian, 

 which is now divided into two stages of equal rank with Cenomanian 

 and Turonian. For the following paleobotanical discussion the writer 

 has adopted the readily understood terminology of the fifth edition of 

 de Lapparent (1906), which is as follows :* 



DANIAN 



MAESTRioHTiAN(from Maestrict = Dokdonian, ~j 



Coquand, 1858). [ UPPER 



Campanian (from the Champagne, Coquand, f SENONIAN. 

 1858). 



Santonian (from Saintonge, Charente, 1 



Coquand, 1858). LOWER 



Coniacian (from de Cognac, Charente, [ SENONIAN. 

 Coquand, 1858). 



1 de Lapparent includes the Montian in the Cretaceous, but the best modern 

 usage as advocated by Dollo, Lemoine and Haug places it in the basal Eocene. 



2 Munier-Chalmas and de Lapparent, 1893, from Aturia (Adour). 



3 Emscher, Schliiter, 1874; Emscherian, Munier-Chalmas and de Lapparent, 

 1893, from Emscher, Westphalia. 



ATURIAN 2 <^ 



EMSCHERIAN 3 



