18 
bouring cliffs and beach and soon found abundance of the same or an 
allied species but when set side by side the difference in size is remarkable. 
The recent shells are at least three or four often six or seven times as large 
as the sub-fossil forms. If of the same species this variation probably 
indicates different conditions of life as regards temperature, moisture and 
food. Their presence would also prove the existence of a land surface with 
vegetation on which the animals subsisted. It therefore appears that 
while some parts of the clay were wet enough to be the habitat of 
Scrobicularia piperata others were sufficiently dry, judging from the 
presence of roots, to support a terrestrial vegetation. In the same clay 
among [the above described shells I found a number of small black glossy 
bodies which had every appearance of being seeds. They were very 
abundant in some spots and I was able to obtain a good many specimens 
though the greater part were broken in clearing them from the matrix. 
They are of course only shells— all the internal part having disappeared. 
I have not been able to determine the species, but should think them most 
likely to belong to some marsh plant. In order to preserve them I am 
obliged to keep them in water having lost a good many at first by allowing 
them. to become shrivelled and cracked.* 
It thus appears evident that this bed of clay with its organic remains is 
one of those patches of submerged land surface which are met with all 
round our south-west coast in the sheltered bays and inlets. At 
Barnstaple Bay it lies where I examined it not below low water mark but 
at other places it may be met with at much lower levels. In so far it is an 
evidence that land once dry enough to support terrestrial or estuarine life 
is now below the tide-level. A change like this may result from either of 
two causes — subsidence of the land or the removal of some barrier which 
once kept out the sea. Were this the only instance the latter might be 
thought a sufficient explanation but occurring as these submerged peat 
beds do at so many places and over so large an extent of country it is more 
reasonable to ascribe their position to a general subsidence of the district 
since the time of their formation. 
* Dr. Hooker, Director of Kew Gardens, at my request very kindly ex- 
amined these seeds but considers it impossible to determine accurately to 
what species they belong without better and more numerous specimens than 
I at present possess. By his suggestion however I am enabled to mention 
that they closely resemble in outward form the seeds of Stellaria media but 
have not the same crenulated edge. This must not be understood as 
at all implying that they belonged to that plant but only as supplying a 
clue to their shape. 
