TRANSACTIONS OF THE SECTIONS. Q7 



On tJie Carstone. By Govier Seeley, 



On the Characters of Dolichosaurus, a Lizard-like Serpent of the Chalk, 



By Govier Seeley. 



The Relation of the Upper and Lower Crags in Norfolk. 

 By John E. Taylor, Hon. Sec. Norwich Oeol. Soc. 



The object of this paper was to prove that the present classification of shells in the 

 Norwich Crag is imperfect, on accoimt of an upper bed being included in the Crao-. 

 The mean percentage of the shells from the two Crags makes the relation of tlie 

 Eed and Norwich Crags very dissimilar, whereas there is really a near connexion 

 between them. By separating the shells of the upper bed, the underlying Noi-wich 

 Crag approaches the Red ; whilst the upper bed itself forms a graduating link 

 between the three Crags and the overlying drift beds. 



After gi\-ing the established percentages of recent and extinct shells in the three 

 Crags, as well as the proportion of Ai-ctic shells found in them, the author men- 

 tioned several places in Norfolk where the Upper Crag mav be seen overlying the 

 Norwich Crag, as at Coltishall, Horstead, Trowse, Thorpe, Whitlingham, and 

 Bramerton. The height of the upper bed ranges above the lower by three to 

 fifteen feet. It is marked by the total absence of freshwater shells, by the 

 paucity of littoral species, and by the abundance of deep-sea shells. It is also 

 distinguished by the greater abundance of Ai-ctic species, as at Bramerton and 

 Thorpe, where several species oiAstmie, Cyprina Mandica, Cardium Grwnlandicwn, 

 Lucina boreulis, and others abound. 



Theauthor also showed that the .shells of the Red and Norwich Crags separated 

 them into distinct beds, whilst the same method would also separate the Upper 

 from tlij Lower Crag in Norfolk. He therefore contended for the existence of 

 four crags, instead of the present classification of them into three. This arrangement 

 established a complete and beautifid sequence between the oldest Coralline Crag 

 and the latest Drift deposits. 



On the Physical Geography of East Yorkshire. By W. Topley. 



On the Lower Greensand of Bedfordshire. By J. F, "Walker, F.O.S. 



The discovery of a new deposit of phosphatic nodules was made about tlu-ee 

 years since in the Lower Greensand of Bedfordshire, in the vicinity of Potton. 

 This bed was formerly quarried for mending the roads, xmtil it was found to contain 

 the nodules for which it is now extensively worked. 



A section at a cutting near Potton Railway Station shows, commencing at the 

 bottom, — 1, sand of different colours (in some places white) ; 2, conglomerate bed 

 (9 ins. to 1 ft. thick) ; 3, sand of different colours, containing oxide of iron, about 

 12 ft. At a coprolite-working, on the left side of the line, looking towards Cam- 

 bridge, a few yards from the edge of the cutting, the bed increases in thickness to 

 two feet. At a large working on the hiU, the conglomerate bed is about six feet 

 thick, tlie section being as follows : — 1, sandstone on which conglomerate rests ; 

 2, conglomerate (G ft.) ; 3, flaggy sandstone, not exceeding one foot in thickness 

 (often less) and sm-face soil. The lower part of the conglomerate here is darker 

 and more indurated than the upper. On the other side of the road is another 

 working, where the nodules lie in a loose sand, and the phosphate-bed is about one 

 foot thick. There are several other workings in the neighbourhood. The con- 

 glomerate contains phosphatic nodules and pebbles in about the same proportion. 

 The bed is dug out, sifted, washed, and laid in heaps, then conveyed mto sheds, 

 where the nodules are picked over by hand. The quantity of phosphoric acid in 

 the nodules varies fi-om 15 to 22 per cent. The deposit consists of fen-uginous sand, 

 more or less indurated, rolled pebbles, light brown nodiUes of phosphatic matter 



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