238 PEOCEEDIJfGS OF THE GEOIOGICAL SOCIETY. [Feb. 22, 



chiefly wing-cases, were found. Trunks of oak trees, some of them 

 60 feet long, were scattered through the peat, and had evidently 

 fallen where they grew ; and from the characters presented by most 

 of them, it would appear that they had grown close together. In this 

 part of the bed, at the level of low water, and beneath a thick layer 

 of moss, the remains of a fire were found. The author suggested 

 that, from the small extent occupied by the remains of this fire, it 

 was probably the result of human agency, as, if it had originated by 

 lightning or by the friction of dry branches, it could hardly have 

 been confined to so small an area. 



The author inferred that no great change in the relative levels of 

 different parts of the bed has occurred^ because at the lowest eastern 

 part the peat had been formed under water, branches and trunks of 

 trees being imbedded in a stratum of grey clay, the wood being 

 much of the same colour as the clay. In one large oak, 5 feet in 

 diameter, there was a hole filled with acorns and hazel-nuts, many 

 of the latter broken open at the end. This the author regarded as 

 the store of a squirrel, and he remarked upon its being the sole 

 trace extant of the existence of squirrels in the forests from which 

 this peat was formed. 



With regard to changes of level, the author stated that, whilst in 

 other places an upward movement has been indicated*, the area ex- 

 amined seems to furnish evidence only of depression. Thus the sur- 

 face of the peat in the supposed old channel of the river Hull is 12 

 feet below the level of low water, whilst the bed of the present 

 river at South Bridge is only 6 feet below that level. The depres- 

 sion of the forest converted the land on which it grew into a marsh, 

 where soft vegetable matter accumulated rapidly and soon covered 

 up the fallen trees, the soundness of the timber indicating no long ex- 

 posure to the weather. As the land continued to subside, the marsh 

 was invaded by the waters of a tidal estuarj^, in which the MoUusca 

 lived whose shells occur in the grey clay overlying the peat, and 

 even in the peat itself. Of these the following forms occur: — 

 Scrobicularia piperata, Cardium edule, Tellina solidula, Hydrohia sp., 

 and Bullina obtusa, all, except the last, in great abundance. 



The arrangement of the trees at the east end of the dock was not 

 such as to indicate that they had been deposited in a current having 

 a constant flow in one direction. The bands of blue clay were 

 bulged out above as weU as below the logs ; and the author accounted 

 for this by assuming that the logs did not yield to compression like 

 the peat, from which, he thinks, an index of the compressibility of 

 peat might be obtained. 



Among the sections accompanying this account, two differ, in 

 showing the Hessle Sand to thin out at the west end of the dock, 

 from the section published in the Society's ' Proceedings ' f . When 

 the latter section was made, the excavations for the dock were not 

 completed, and the sand underlying the silt in borings westward 



* Quart. Journ. Geol. Soc. vol. xxiv. p. 157. 

 • t Quart. Journ. Geol. Soc. vol. xiiv. p. 182, fig. 14. 



