430 MR. G. AV. LA.MPLUGH ON THE 



be accepted, for the mapping of Holderness distinctly showed two 

 independent gravels, the one marine and dipping regularly seaward 

 beneath lioulder-clay till it sank beneath the sea-level, while the 

 other capped the higher elevations near the coast, was coarse and 

 irregular, and only contained fragments of shells washed out of the 

 Boulder-clay, as is the case in the gravel-mounds of Plamborough. 



The fauna of the marine gravels is such as might have lived at the 

 spots where the fossils now occur. It is usually purely marine ; but 

 opposite the gap in the Wolds through which the Humber flows 

 freshwater shells and bones of land-mammals occur abundantly, and 

 freshwater shells are also found at one other spot, opposite the mouth 

 of a Wold valley in J^orth Lincolnshire. If the gravels had been 

 pushed up and reconstructed by the ice, as suggested by the 

 Author, it is curious that the slight variations in the fauna should 

 agree so closely with variations in the local conditions where the 

 gravel is now found, and not with variations we should expect to 

 find farther seaward, 



Mr. Whitakee asked if the " mounded gravels "" might not be 

 eskers, like some ridges of gravel seen in Western Norfolk, which 

 had been thought to be eskers. 



Mr. E. T. Newton pointed out that, although most of the species 

 of mammals found at Sewerby were also found in the Norfolk 

 Forest-bed, yet none of them were forms characteristic of that 

 horizon ; but, on the other hand, it was just such an assemblage of 

 species as might be expected in an undoubted Pleistocene deposit. 



Prof. Hughes, referring to the diagram on the waU, pointed 

 out that much depended upon the establishment of the true relations 

 between the Basement Clay and that represented as overlying the 

 talus at the base of the cliff. If the talus were derived from the 

 cliff against which it lay, the form of the cliff should be parabolic in 

 section ; but if the deposits now lying against the Chalk-face had 

 slipped against a vertical sea- cliff, then the evidence as to their 

 relative age from their present relative position was open to question. 

 As the fauna agreed so closely with that of the gravels of Cambridge- 

 shire, which could be proved to be post-Glacial, he was inclined to 

 avail himself of any escape from the conclusion that it was of pre- 

 Glacial or even Glacial age in Yorkshire. 



The President remarked that he was reminded of an exploration 

 of the Yorkshire coast made by him with Sir Andrew C. Pamsay, in 

 the early days of glacial geology, when they examined many of the 

 sections described by the Author of this paper. One of the obser- 

 vations which they made on that occasion was that, while many of 

 the stones in the Boulder-clays might have come from the Scottish 

 Highlands, there was a scarcity or absence of the rocks of the South 

 of Scotland which ought to have been there, had the general mass 

 of materials come from Scotland. These observations, which were 

 not published, have been confirmed and extended by later writers, 

 but the details of the drifts have never been so carefully worked 

 out as they have now been by Mr. Lamplugh. 



The Author said that he was quite prepared for the difficulties 



