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like the teeth of a comb or short and bhmtly rounded. 

 Moreover the anatomy of the creeping stem affords 

 a ready means of identification. We have satisfactory 

 evidence of the occurrence of Gleichenia in European 

 floras during both the Jurassic and Cretaceous 

 periods. Numerous fragments of plants were obtained 

 some years ago, not far from Brussels, from the Wealden 

 strata in which the famous skeletons of Iguanodon 

 were discovered. Visitors to the Natural History 

 Museum in Brussels are no doubt familiar with the 

 skeletons of this enormous herbivorous animal : in 

 the same gallery are exhibited the remains of the 

 fossil plants from the Iguanodon beds. Some of 

 these fragments are pieces of fern fronds identical 

 in form with those of existing Gleichenias. The 

 microscopical examination of some exceptionally well 

 preserved fragments of Wealden stems discovered by 

 Prof. Bommer of Brussels enabled him to recognise 

 the Gleichenia type of structure and thus to confirm 

 the inconclusive evidence furnished by fragmentary 

 leaves. The most interesting records in regard to 

 the former occurrence of Gleichenia in Northern 

 Europe we owe to the late Oswald Heer of Zurich, 

 who has described many examples of Gleichenia 

 fronds from rocks of Lower Cretaceous age in 

 Disco Island on the west coast of Greenland in 

 latitude 70° N. The same type of fern is recorded 

 also from upper Jurassic beds in the north-east of 



