126 J. GUNN ON THE FOREST-BED SERIES AT 



ing that Messrs. Wood and Hariner, in their Palaeontographical 

 Monograph almost ignore them, except at the Pakefield-Lighthouse 

 Gorge, near which they represent them as dipping down or trun- 

 cated and not reappearing throughout the entire length of the coast. 

 They average about 12 feet in thickness. 



No. 2 has generally been regarded as the Middle Drift ; but, from 

 the admixture of occasional plots of pebbles, I am inclined to call it 

 the Pebbly Bed, or YVestleton Sands. The upper part is, perhaps, 

 Middle Drift. It is about 15 feet thick. 



No. 1 represents a grand display of the Upper Boulder-clay, ave- 

 raging 15 feet; above is the warp and humus, 4 feet. 



If I have erred in any respect, I trust I shall be corrected by the 

 geological surveyors now at work in the neighbourhood. 



Discussion. 



Mr. A. Tylor inquired whether the lowest beds in Mr. Gunn's 

 section represent the Antwerp Crag, as in this case the succeeding 

 deposits would represent the other three Crags. Great quantities of 

 fossil bones and teeth had been collected at Antwerp during the con- 

 struction of the fortifications of that city. 



M. Cuarleswotii could not understand how the Norwich Crag- 

 can be above the Forest-bed. Be mains of Mastodon have not been 

 found in the Forest-bed ; but they occur in the Norwich Crag. 



Mr. Gunn said that it was now agreed at Norwich that the so- 

 called Mammaliferous Crag is not really Mammaliferous, but that 

 the mammalian remains found in it are derived from the Stony Bed 

 resting immediately upon the Chalk. Dr. Falconer entertained the 

 same opinion. 



Mr. Charlesworth stated that what he wanted was the evidence 

 upon which the bed indicated in the section brought before the 

 Society by Mr. Gunn was identified with the Norwich Crag. 



Mr. Gwyn Jeffreys remarked that certain Arctic shells occur 

 in the Chillesford Clay, and instanced particularly Leda hyperborea, 

 a species which was obtained from a depth of 450 fathoms in the 

 Norwegian Sea, and which he had found in 175 fathoms at the 

 entrance to Baffin's Bay. The Ledce are deep-water species ; and 

 the occurrence of L. hyperborea in the Chillesford Clay would seem to 

 indicate that that deposit had been formed at a considerable depth, 

 and afterwards upheaved. 



Mr. Whitaker stated that he had been with Mr. Blake along the 

 coast to examine the lower beds referred to by Mr. Gunn. Mr. 

 Blake had clearly established that in the case of these beds, which 

 were only about 20 feet thick, different observers had given different 

 names to the same things, and in fact had given names to con- 

 ditions and not to beds. He was glad that Mr. Gunn had called 

 the " Eootlet-bed " by that name, as it was certainly not a " Forest 

 bed " though it had been so called. From the varying nature of the 

 coast, and the fact that the sections were interrupted, he could easily 

 understand the difficulty that had been experienced in establishing 



