CROFTS : NOTES ON ALEXANDRA DOCK EXTENSION, HULL. 249 
nature, on which the peat bed rests with the roots of trees in 
places running down into the boulder clay itself. This gravelly 
capping appears to be the original upper portion of this clay, 
and consists of sand and rounded and angular fragments of the 
boulders common to this clay, some of which are so angular that 
they can hardly have been subjected to any attrition at all, and, 
as they are often quite on the top amongst the peaty fragments, 
water cannot have subjected this capping very much to its 
disturbing influence, though the close of the glacial period is 
generally associated with flooding. 
The peat bed, which in the northern portion of the dock 
follows the boulder clay, further towards the south rests upon 
the red stoneless clay, sometimes having a gravelly capping as in 
the case of the boulder clay. 
This peat bed is similar in some respects to that of the 
ancient meres of Holderness. It covered the whole of the district 
round Hull, reaching to Hessle on the west, where it gradually 
fades away until at last nothing but a fine line marks the 
junction of the boulder clay and warp. The peat here did not 
extend further south than about 200 ft. north of the southern 
wall of the dock, and beyond this there were no indications of 
tree roots having at any time penetrated the underlying beds, 
but the red stoneless clay at the south-east corner of the dock 
had a considerable number of roots of reeds running through 
it, and in some places its sandy base had traces of the same 
kind, although where the peat itself existed there were but few 
roots of this character. 
The peat consisted of leaves, bark, wood, stumps of trees 
with, in some cases, the roots going down several feet into the 
glacial beds below. No prostrate trunks of any size were noted, 
although this is a common feature of this bed in this neighbour- 
hood. The oak {Quercus pedunculata), cherry (Frunus padus), 
birch, and hazel were represented. Beetles' wing cases were also 
found. 
One of the most instructive features of this bed is the fact 
that its surface 13 ft. below O.D. is 25 ft. below the level of 
