FLORAS OF THE PAST. 457 



the rich collections which are now in the British Museum 

 have been discovered ; and considerable credit is due to 

 Mr. Rufford of Hastings for having been the means of 

 obtaining an unusually fine series of plants from the Wealden 

 beds on the Sussex coast. 



In the Island of Portland and on the neighbouring main- 

 land coast near Swanage and Lulworth there is exposed a 

 succession of strata, for the most part of freshwater origin, 

 but containing a few intercalations of marine deposits. This 

 series — long known as the Purbeck beds — is closely con- 

 nected with the succeeding Wealden strata, both as regards 

 fossil contents and conditions of deposition ; it forms a part 

 of the delta and lagoon deposits which were laid down 

 in Southern England at the close of the Jurassic period. 



The Wealden plants occur for the most part as frag- 

 mentary portions of twigs and leaves which were floated 

 into their present position by the quiet waters of a river 

 which rivalled in size some of the largest streams of to-day. 

 In the Purbeck beds, and in the Wealden of Brook Point in 

 the Isle of Wight, we have huge pieces of coniferous wood 

 and cycadean stems which grew where their remains are 

 now found as fossils, or were floated a short distance from 

 the neighbouring forests. 



From France but few Wealden plants have been re- 

 corded. In Northern Germany, on the other hand, there 

 is an extensive development of freshwater Wealden beds, 

 which has supplied Schenk 1 and other continental writers 

 with rich material for palaeobotanical study. Plants of the 

 same age have been found also to the north of the Hartz 

 Mountains and elsewhere. From Austria, Portugal/ 2 Russia 

 and the arctic regions 3 Wealden plants have also been 

 obtained. The famous Belgian locality of Bernissart, which 

 has furnished the Brussels Museum with more than twenty 

 skeletons of Iguanodon, has afforded a few samples of 

 Wealden vegetation. 



There are a few other localities in Belgium — notably 

 Bracquegnies — where plants have been found, but the 



1 Schenk (1) and (2). 2 Heer ^ and Saporta. 



3 Heer (2), Nathorst (2). 



