TRANSACTIONS OF THE SECTIONS. 65 



phyllum, a Heliolites (Porites), with small tubes ; Syrinyopora {Harmodiies) with Ha- 

 lysites catenulatus {Catenipora escharoides) , and Stromhodes striatiis, Milne Edwards, 

 fossils characteristic of the Niagara and Onondaga limestones, and in America never 

 found in the lower rocks ; with these occur Atrypa reticularis in plenty, a Terebra- 

 tula with three raised plaits, and very rarely a Leptceiia or Strophomena. One or 

 two spiral shells recall the shapes of some of Hall's species o( Holopea, but are too 

 imperfect for identification ; and there is a long spiral shell, like Murchisonia gracilis. 

 Encrinurus punctatus is the only trilobite. 



The most striking shell perhaps is a species of Ormoceras, the short broad siphun- 

 cles of which are well preserved, while the shell has decayed ; and these so much 

 resemble those figured by Dr. Bigsby and Mr. Stokes in the Geological Transactions, 

 2nd series, vol. i. pi. 30, figs. 4, 5, 6, 7, that we think there can be no doubt of their 

 identitj'. And it is very interesting, as bearing on the question of age, that these 

 were found at Drummond Island, the only limestones of which are Upper Silurian. 



Indeed the whole aspect of this collection, small as it is, is as strikingly Upper 

 Silurian as that of the former one was Lower Silurian. The preponderance of the 

 Catenipora, Favosites and Stromatopora, &c., is characteristic of the higher rocks, and 

 they are associated with Pentamerus oMongus (the characteristic fossil of the Clinton 

 group, which may be regarded as the base of the upper division), and this shell in 

 America is far more limited in its vertical range than it is in Britain. 



Professor E. Forbes exhibited the new species oi Maclurea referred to by Mr. Salter, 

 and its operculum, and stated that he regarded it as one of the floating forms which 

 appear to have been common in the Silurian period. 



0)1 the Occurrence of a Stratum of Stones covered with Barnacles in the Red 

 Crag at Wherstead, near Ipswich. By Sir Charles Lyell, F.R.S. 



It has been observed that in the Red Crag of the neighbourhood of Ipswich, and 

 generally throughout the area occupied by that formation in Norfolk and Suffolk, the 

 marine organic remains are not now in the places where the animals to which they 

 belonged lived and died. They are mixed with pebbles, and often, like tliem, bear the 

 marks of having been rolled. The valves of the bivalve moUusca are found detached 

 one from the other, and neither they nor the univalve shells are arranged in groups 

 as they lived at the bottom of the sea. They look as if they had formed portions of 

 shifting sand-banks, or as if they had been drifted from some other place to that where 

 they are now met with. Every exception, therefore, to so general a rule deserves no- 

 tice, and I shall mention one now to be seen in the Crag within a few miles of 

 Ipswich, about 500 yards south of the vicarage-house of Wherstead, to which attention 

 was called by the Rev. Barham Zincke of Wherstead. The shelly red crag here laid 

 open has a vertical thickness of from 10 to 12 feet, and is overlaid by 8 feet of sandy 

 and gravelly beds without fossils. The shelly mass presents the usual characters of 

 this formation, and among others, that of having the separate valves of the Pectun- 

 culus, Mactra, Cardita, Pecten and Terebratula with their concave sides turned down- 

 wards, almost without one exception. Near the top ef the shelly mass, usually within 

 18 or sometimes 8 inches of it, a stratum occurs consisting of imi-ounded chalk flints 

 intermixed with some well-rounded flint pebbles. The upper portions of these stones, 

 which are of various sizes, are encrusted with barnacles from which their lower sur- 

 faces are free. The barnacles consist chiefly of a littoral species, Balanus communis, 

 and another nearly allied to it. The longest of the stones obtained by Mr. Zincke from 

 this bed, and which he has brought to the meeting, is an unrounded chalk flint, mea- 

 suring no less than 22 inches in length, by 16 in breadth, and 7 in height. It sup- 

 ports on its top and sides about ten groups of barnacles, hut none of these are found 

 on the under side of the stone, where it must have rested on the bottom of the sea. 

 The same remark holds good in regard to all the other stones and pebbles spread 

 through the same stratum. Among these Mr. Zincke and I observed a small copro- 

 lite, or one of the bodies commonly so called, the top of which was covered with bar- 

 nacles, while all the lower portion was smooth. The pebbly stratum containing these 

 Balani is overlaid with shelly crag, of somewhat fine materials, and of slight thickness, as 

 1851. 5 



