#rmrrjemcof k Sl^cll-kanng 
6rakl at litimball |slantr. 
By HERBERT BOLTON, E.R.S.E., CURATOR OF 
THE BRISTOL MUSEUM. 
I 
N March of the present year I was informed by Mr. 
Pearce, Resident Engineer upon the Avonmouth 
Dock Works, that at a considerable depth in the excava- 
tions at the south-east corner of Dumball Island, a shell- 
bearing layer had been met with which might prove of 
interest. On March 28 I visited the dock Works, and was 
shown over the ground by Mr. Pearce. The latter gentle- 
man directed my attention to the excavations which were 
proceeding for the wall of the inner gates of the lock which 
runs along the south-eastern side of the old Dumball 
Island. At a depth of about 24 feet from Ordnance Datum, 
or 44 feet from the surface, a layer of sand, mud, and fine- 
gravel had been met with having an average thickness of 
five and a half feet. The whole surface of this layer could 
be seen dotted over with the separated valves of Tellina 
balthica. An examination of the material showed that the 
shells were distributed throughout the mass, and were 
not confined to the surface layers only. 
A vertical section of the deposits at this part of the 
Dumball Island has been kindly furnished 
Pearce. It is as follows : — 
Mud . ..... 
Mud and loam .... 
Sand, mud, and fine gravel, -with shells 
Stiff clay ...... 
Ballast (Gravel) .... 
me 
by 
ft. 
in. 
33 
0 
11 
6 
5 
6 
6 
0 
10 
0 
66 
0 
241 
