Geological Society of London. 385 



Mr. Prestwich, in reply, explained that lie did not intend to omit 

 the list of mammalian remains of the Ecd Crag, tables of which 

 were appended to the paper, the greater part of them, however, he 

 regarded as derivative. With regard to the relation of the Chilles- 

 ford-beds to the Forest-bed, he had never seen a section in which the 

 latter was found beneath the former — the Chill esford beds at Easton 

 Bavent were underlain by sandy beds referable to the Norwich 

 Crag. He considered that some division in the lower bed, as sug- 

 gested by Mr. Searles Wood, was to be found. 



II. June 3rd, 1868. — 1. ''On some Genera of Carboniferous 

 Corals." By James Thomson, Esq. Communicated by Dr. P. 

 Martin Duncan, Sec. G. S., etc. 



Mr. Thomson gave a resume of the diagnostic peculiarities of 

 Cyathophjllum, Goldfuss, Clisiophjllum, Dana, Aulophyllum, Milne- 

 Edwards and Jules Haime, and Cyclophyllum, Duncan and Thomson. 

 The author then noticed that the separation of these genera was in- 

 evitable and necessary, from the ordinary rules of the classification 

 of the Zoantharia. He concluded by remarking upon the evident 

 structural distinctions between Clisiophyllum, Aulophyllum, and Cyclo- 

 pJiyllum. 



Discussion. — Dr. Duncan said that the existence of a columella 

 was a generic distinction in Kecent and Mesozoic corals, that the 

 type of the Palaeozoic Cyathophyllidse was reflected in the Lower 

 Liassic coral-fauna of South Wales and the west of England, and 

 that there was a necessity for the same principles of classification in 

 the Paleeozoic and in the Kecent coral-fauna. There was a gradation 

 from the Rugosa to the Aporosa. 



Prof. Huxley remarked that the structures of the specimens of 

 the difierent genera proved that there were great difficulties in ac- 

 cepting Agassiz's opinion that these old forms were not Zoantharia. 



2. " On the Pebble-beds of Middlesex, Essex, and Herts." By 

 S. Y. Wood, Jun., Esq., F.G.S. 



The author described two groups of pebble-beds. The first of 

 these, composed of rolled flint only, and confined to the outliers of 

 Bagshot sand scattered through Middlesex and Essex, he considered 

 must be referred to the deposit of the Bagshot sea during its reces- 

 sion from these counties ; unless the Lenham beds could be held to 

 establish the existence of an older Pliocene sea over Kent, in which 

 case this group of pebble beds might be connected with that event. 

 The second group of pebble beds was the same as that lately de- 

 scribed by Mr. Hughes in Hertfordshire, as " gravel of the higher 

 plain" of that county, which is found intermittingly to underlie the 

 Glacial clay at high levels. Mr. Wood objected to Mr. Hughes' 

 view that this bed was anterior to the gravel of the lower Hertford- 

 shire plain (which is of Middle Glacial age and underlies the Glacial 

 clay at lower levels) ; regarding it as merely a modification of the 

 latter at the close of the Middle Glacial period, due to much of it 

 having been, at these high levels, constructed out of the pebble beds 

 of the first described group. 



