SHEPPARD : INTER-GLACIAL GRAVELS OF HOLDERNESS. 
5 
Several of the chalk boulders are well rounded and bored with 
Cliona) and Pholas crispata. The holes in the pebbles occasionally 
contain the shells in a perfect state of preservation, though some- 
times sand takes the place of the shells. Other chalk pebbles are 
cracked from the centre outwards, in a similar manner to the 
cracks seen in septarian nodules. 
The boulders of gneiss and schist are occasionally very rotten, 
breaking into powder at the stroke of the hammer. Some, however, 
are as fresh as if recently broken from the heart of a large block. 
No doubt the former boulders would be partially decomposed before 
being torn up from the floor by the ice. 
There are no well-marked, ice-scratched stones. One or two, 
however, have been noticed, although the scratches were nearly 
obliterated owing apparently to the pebbles having been rolled in 
water. 
Whilst digging at the gravel in almost the centre of the pit, at 
a depth of 16 feet, I unearthed a boulder of rhomb-porphyry {& 
characteristic Norwegian rock;, well rounded, and about six inches 
long and four inches wide. The position of this boulder, 16 feet 
from the surface, and in central Holderness, six miles from the sea, is 
a good case wherewith to test Sir H. H. Howorth's hypothesis that 
these Norwegian boulders had been brought over to England as 
anchors by the evidently exceedingly industrious Vikings. See 
Nature, May 24th, 1894.- 
The Shells. — These are found in different quantities and in 
various conditions (though they all have a waterworn appearance) 
in all parts of the pit. As- already stated, in some places they are 
represented by minute fragments, whilst in others they are pre- 
served whole. Cyrena fluminalis, Cardium edule, Tellina balthica, 
Ostrea edulis, and Buccinum undatum can be found in plenty. It 
will thus be seen that the shells here resemble those found at Kelsey 
Hill, both in species and numbers, though they are slightly different 
in the matter of relative prevalence. 
* Since the reading of the paper I have found another example of rhomb- 
porphyry of even larger dimensions in the undisturbed gravel. The find can 
be attested by several members of the Hull Scientific Club, who saw the stone 
projecting from the face of the section 12 feet from the top, and firmly fixed 
in the ferruginous conglomerate before mentioned. 
