3rd February, 1886. 



The President, Mr. W. H. Patterson, M.R.I.A., in the Chair. 



William Swanston, Esq., F.G.S., read a Paper upon an 

 IMPORTANT LOCAL GEOLOGICAL DISCOVERY. 



Mr. Swanston stated that the notes he had been requested 

 to bring forward referred to a fossil that had been found 

 some time since in the white limestone, or chalk, quarry 

 at Whitewell, and which had now been presented to the 

 Museum by the proprietor (Mr. Turner, of Mountain Bush). 

 The fossil was portion of the vertebral column of a huge reptile, 

 known to the geologists as Mosasaurus gracilis, of Owen, and 

 whose nearest living representative is the crocodile. Mosasaurus 

 gracilis belonged to a family of giants, remains of specimens 

 having been found that must have measured fully 25 feet 

 in length ; while its better known relative, Mosasaurus princeps, 

 attained the extraordinary length of 75 feet. The first record 

 of our species as British was made by Dr. Mantell, in his 

 "Geology of the South-East of England." Detached frag- 

 ments have from time to time since been found in English 

 and Continental^strata, and from these it has been pretty 

 clearly made out that the creature's head formed about one- 

 sixth of its entire length, in which respect it resembled the 

 crocodile, but in the shortness of its tail and other respects it 

 was^altogether unlike it. From the examination of its remains 

 it can be pretty safely conjectured that it was aquatic and 

 possibly marinejn its habits. Its feet were paddle-like in form 

 — more adapted for swimming than for progression on land ; 



