part 1] OF THE UPPER CRETACEOUS IN HUNGARY. 109 



years, turns out to be in reality nothing else than the poor remains 

 of an older and richer but less-known fauna. 



Thus we have not only to deal with a primitive fauna, but with 

 one in which the genera are reduced in numbers while individuals 

 are abundant. Apart from this, the small size of the Dinosaurs 

 should be noted, the biggest not exceeding 18 feet in length, tail 

 included. 



IV. Pal^ogeographical Data. 



Leaving now the palEeontological aspect of the question and 

 reverting to the geological aspect, we find by consulting the most 

 accurate paheogeographical maps of the Cretaceous Period, such as 

 A. de Lapparent's (41) or E. Haug's maps (29), or those of T. Arldth 

 (3), that the southern part of present day Europe, which had been 

 a great mass of dry land during Neocomian times, had become 

 during the Cenomanian a mere archipelago. Apart from the 

 island which comprised the western part of Great Britain, 

 Normandy, and Western Spain, and a second island in the centre 

 of Germany, one island covered the South of France, Corsica, and 

 Sardinia, another island or part of one embraced the Alps, Hungary, 

 Serbia, Macedonia, and Thrace , and still another the Dobrudsha 

 and a great part of Southern Russia. Prom the great continent 

 that lay in the north, and extended eastwards towards Asia, these 

 islands were separated by a continuous channel running from west 

 to east. Until Lower Senonian times the distribution of land and 

 water seems to have remained practically the same. Between the 

 Lower and Upper Senonian occurred, as I succeeded in establishing 

 in co-operation with Prof. Murgoci, that great tectonic movement 

 which produced the present Carpathian ranges, and therewith the 

 main outlines of recent European topography. This movement 

 was evidently followed by a period of local emergence ; but, not 

 long afterwards, the emerged regions were partly invaded once 

 more by the sea. Perhaps the invasion occurred in the rear of 

 the overthrust masses, while the overthrust was going on. 



The Upper Senonian sea did not in Eastern Hungary invade that 

 great tract of land which had been covered by its predecessor, but 

 the newly-formed depressions ; thus, in accordance with the new 

 topography, it was more or less restricted to the depressions still 

 existing. Two small islands were left uncovered, one corresponded 

 in some way to the actual mountains of Bihar, another in a vague 

 manner to the Transylvanian Alps. These were the small areas 

 to which the Dinosaurs were restricted during Upper Senonian 

 time. 



As the brackish-water beds of Alvincz show, the land soon began 

 to emerge again, and the areal range of the Dinosaur extended ; 

 finally, the isolated tracts united and formed again a large mass of 

 dry land, with freshwater lakes and great freshwater swamps 

 between them. These lakes lay where during the overthrust, 

 behind the overthrust sheets, depressions had been formed. While 



