540 



On the Finding of Shells in the Boulder Clay near Berwick- 

 on-Tiueed. By William Gunn, F. G. S. of H. M. Geo- 

 logical Survey. 



Most people who have been to BerwIck-on-Tweed will know 

 the pleasant path called " The New Walk " which leads along 

 the north side of the river from the end of the old bridge, past 

 Castlehills, towards New Water Haugh. At the Grove House 

 the path enters a wood where the river bank is a mass of glacial 

 deposits, mainly clay, with some sand and gravel bands. The 

 ground is very uneven and insecure, in fact little else than a 

 series of slipped masses of drift, which is constantly being under- 

 mined by the stream, and the paths are often changing. Here 

 after wet weather fragments of marine shells may be seen 

 occasionally lying on the surface of the clay. I cannot remember 

 when I first began to notice them, but in the spring of 1882 I 

 determined to make a collection of them and see if any of the 

 fragments were large enough for the species to he made out. 

 In this object I was assisted by one of my sons, A. E. Gunn. 

 Of course none of the fragments we first observed and collected 

 were in situ in the clay, but we eventually succeeded in tracing 

 them upwards till we found them in situ in the clay itself, and 

 in gravelly bands in the clay at heights of from 75 to 90 feet 

 above the ordnance datum line. The part where the shells are 

 most abundant is near the east end of the wood, and is distant 

 from the sea-shore at the end of Berwick Pier, about a mile and 

 a-half in a straight line. From the- fine old bridge it is a walk 

 of about a mile and a-quarter along the river side. My best 

 thanks are due to my colleague, Mr G. Sharman, who kindly took 

 the trouble to go over the fragments, when he was able to make 

 out the following list of species : — 



Ostrea. Tellina Balthica, Linn. 



Pecten. Cyprina Islandica, Linn. 



Astarte borealis ? Chemn. Turritella communis, Eisso. 



Astarte sp. Littorina littorea, Linn. 



Cardium edule, Linn. Buccinum ? 



Saxicava rugosa, Pennant. Dentalium abyssorum ? Sars. 



Mya truncata, Linn. Fragments of Belemnites, derived. 



