Br. a. Woodward — On Iguanodon MantelU. 13 



discover}^ of Iguanodon remains was made in the Wealden — during 

 which time similar reptilia, more or less complete, have been ex- 

 humed on the Continent, in England, and in North America, in 

 strata varying in age from the Trias to the Chalk, — numerous perfect 

 specimens should have lately been met with in their original gise- 

 ment, the Wealden formation, from which the first was obtained ; 

 not however in Sussex, but in Belgium. Their preservation is due 

 to a very singular circumstance. In the goUiery of Bernissart ' — 

 between Mons and Tournai near the French frontier — the Coal- 

 measures (which are overlain by the Chalk-formation and by thick 

 Quaternary deposits) are fissured in many places by deep valleys or 

 chasms more than 200 metres deep.'* These must have been formed 

 by denudation and dislocation of the strata in post-Carboniferous 

 times, and were open gorges in the old land-surface in the Wealden 

 period.^ Into this vast abyss were precipitated, by some Cretaceous 

 debacle, twenty-three huge Iguanodons, numbers of fish of the 

 genera Lepidotus, Opliiopsis, and Microdon ; a Batrachian ; several 

 species of Chelonians ; and Crocodilians — equally perfect with the 

 Iguanodons ; — and numerous ferns of the genus Zonchopteris, Pe- 

 copteris, Alethopteris, Sphenopteris. Gleiclienites and Gleiclienia ; agree- 

 ing with those described by Dunker from the Wealden of Hanover, 

 and by Mantell from that of the south-east of England.* 



The ossiferous deposit is separated from the steep walls of coal- 

 shale bounding the chasm by a talus 10 metres thick, composed of 

 debris of the coal-formation. The layers are composed of finely 

 laminated blackish clay, interstratified with veins of grey sand and 

 fragments of coal. 



The skeletons are imbedded in concretionary masses in the fine 

 clay-sediment with fishes and plants, and indicate a repetition of 

 ossiferous deposits at different levels, more or less widely separated 

 by beds of unfossiliferous clay. The beds themselves are inclined 

 at 70° against the sloping talus, but their inclination diminishes 

 rapidly and is reduced to only 5° at a distance of 12 to 15 metres 

 from the sides of the chasm. The discovery was first made known 

 in 1878, and three years were subsequently spent by M. de Pauw in 

 extracting the great series of fossil-remains from the pit-shaft, the 

 bones being brought up from a depth of 322 metres.^ It must have 

 been no small inconvenience and loss to the owners of the Sainte- 

 Barbe coal-pit, to allow M. Dupont, the Director of the Brussels 

 Museum and his Assistants, to carry on their researches for so long a 

 period, and bring to bank with care so large and bulky a collection, 



1 " Sur la decouverte d'ossements ^Iguanodon., de poissons, et de vegetaux dans la 

 fosse Sainte-Barbedu charbonnage de Bernissart: " par M. Ed. Dupont, Membre de 

 I'Academie, Directeur du Musee Royal d'Histoire Naturelle de Belgiqne. (Bulletins 

 de I'Academie Eoyale des Sci.etc. de Belgique, 2^ Serie, Tome 46, Bruxelles, 1878, 

 pp. 387-4U8.) 2 650 feet. 



^ These old land surface -contours are now quite obliterated by deposits of later 

 date which iill up and conceal them, and, save in these deep gorges, the Wealden 

 formation has been completely destroyed and removed by subsequent denudation. 



* Mantell's Geology of the South-east of England, 8vo. 1833, and Mantell's 

 Wonders of Geology, 8vo. 1838-1858 (7 editions). * Uver 1000 feet. 



