274 Reports and Proceedings. 



vertical distance above tlie true Norwich Crag was anotlier bed of 

 sbells. This bed varied in height above the lower one from twelve 

 feet to two. Hitherto it has been the custom to take the mean of 

 the two beds, and sum up the total of species as belonging to the 

 Norwich Crag, totally ignoring the characters of the upper and 

 lower beds. By limiting the per centage of shells found in each, 

 we arrive at far different conclusions to those commonly received, 

 and he believed the difference between the two beds to be as distinct 

 and as great as it was between any of the other crags. It followed 

 from this that we must either regard the upper bed as di. fourth crag, 

 or must regard the lower as approximating in age to the Ked Crag. 

 He was inclined to the former theory, and believed that, when well 

 worked, the four crags would be found to pass gradually into each 

 other, and to be connected with the Glacial series, more closely than 

 has yet been seen. His own investigations proved that the upper 

 bed was of a far more distinctly Arctic character than the lower. The 

 same shells might be found in each, but the proportion was vastly 

 different. 



Mr. Taylor then described several localities where he had ob- 

 served the two separate crag deposits in superposition, at Coltishall, 

 Horstead, Bramerton, Thorpe, Whitlingham, and Postwick. 



From these facts he drew tliree conclusions, viz., the total absence 

 of fresh-water shells, and the general predominance of those usually 

 found in deep water, indicated that the upper bed was formed 

 under more distinctly marked marine conditions ; secondly, the 

 paucity of littoral shells bore out this supposition ; and, thirdly, the 

 distinct Arctic or " Northern " features, which everywhere are 

 found in the upper bed, marked it off definitely from that below it, 

 and indicated a more rigorous climate during its deposition. The 

 paucity of species in the upper bed, when compared to the richness 

 and variety of those found in the lower, was another argument in 

 favour of their distinct character. Doubtless the lower bed. con- 

 tained more " Northern " shells than the Eed Crag of Suffolk, and 

 thus showed an increasing cold. The upper bed supplemented this 

 theory, and proved that the cold was increasing, whilst the succession 

 of Glacial clays and foreign boulders carried out still farther the 

 belief in a gradual and increasing rigour of climate. The " Iron 

 Pan," which usually lies five or six feet above the upper bed, was also 

 marked with the impressions of shells, chiefly Cardium, Mytilus, 

 and Pectens, proving the marine character of the entire series, from 

 the Coralline Crag to the latest Boulder-clays and sands. He con- 

 sidered the custom hitherto adopted of taking the mean of the shells 

 from the upper and lower beds, and calling the per centage that of 

 the Norwich Crag, had misled geologists as to their relative ages 

 and character. The various crags seemed to glide into each other, 

 and the upper or fourth crag was the connecting link between the true 

 Norwich Crag and the Glacial series. 



The thanks of the society were then tendered to the author of the 

 paper, and the President requested Mr. Henry Woodward, F.G.S., 

 who was present, to make a few remarks on the paper. 



