vi PREFACE TO THE 



and zeal his quest of fossil remains in the cliff of Lower Lias at Charmouth, where 

 he first came upon that indication, and he kindly complied with my desire to send 

 the block of matrix indicating an included bone. I successively received from him 

 twelve additional blocks, and superintended the careful operations of our skilled 

 Museum masons, the results being an almost complete skeleton of the extinct 

 Reptile. 



Other fossil evidences subsequently submitted to me served for a definition of 

 characters of a Crocodilian genus Poikilopleuron, 1 and of a Dinosaurian genus 

 Chondrosteosaurus. 1 The volume issued by the Palseontographical Society for the 

 year 1876 contained the Monograph on these extinct Reptilia of the British 

 Wealden and Purbeck Formations. A trunk vertebra of a Chondrosteosaur from 

 the Isle of Wight, the subject of Plate VI, equals in size the corresponding bone 

 of a full-grown elephant. The exposed canal of the myelon (spinal marrow) of 

 an eagle is introduced upon the plate, exposing that canal which lodged the corre- 

 sponding sensory and motory centre in the gigantic terrestrial, cold-blooded 

 vertebrate, to exemplify the contrasted relations of the nervous to the muscular 

 machinery in an active, warm-blooded and in a sluggish, cold-blooded vertebrate 

 animal. The insulation of the actual locality of the fossil took place long after the 

 Continent of the Secondary geological period of our planet had been broken up. 



Subsequent researches in formations of the Wealden and Purbeck periods 

 unearthed fossil remains with characters on which the Crocodilian genera Gonio- 

 pholis, Petrosaurus, and Suchosaurus were founded. The descriptions and figures 

 form the Supplement, No. 8, of the Monograph on the Reptilia of the Wealden 

 and Purbeck Formations, issued by the Palseontographical Society in 1878. 



Characters of huge extinct Flying Dragons (Pterosauria) from British localities 

 of Gault, Wealden, Kimmeridgian, Oolitic, and Liassic formations, were described 

 and figured in the volume issued by the Palseontographical Society for the year 

 1873 ; namely, pages 1 — 14 of the present Monograph. 



In the volume for 1875, pages 15 — 93, osteological modifications in fossil 

 Reptilian remains from British Secondary formations were described and figured, 

 which interest the comparative osteologist more than even the palseontologist. 



The proportions of the skeleton of one and the same individual of a huge extinct 

 Reptile are unusually great in the type of the genus Omosaurus, fossilized in the 

 K.immeridge clay at Swindon. 



The history of its discovery exemplifies the importance and advantage of noting 

 indications of an organic constituent in a formation, the utility of which justifies 

 the organisation and operations of a commercial company, and the valuable result 

 to science in arresting the disturbance of such indications until a geologist 

 cognizant of the zoological characters so indicated has seen the fragment, and 



1 See Supplement No. 7 of the Monograph on the Eeptilia of the Wealden and Purbeck Formations. 



