386 Letter Mr Bowdich to Professor Jameson „ 
A1 the branches and trunks appear to belong to the same 
sort of tree, (of which there seems to have been a small fo- 
rest in that spot), and that evidently a Dicotyledon ; but more 
than this, I do not think our present knowledge of the compa- 
rative anatomy of timbers is sufficiently advanced to determine *. 
The sand is calcareous, whether from the destruction of frag- 
ments of transition limestone (found beneath the basalt at St Vi- 
cente) in the bed of the ocean, or from comminuted shells, I 
will not venture to pronounce, although I incline to the former 
opinion. The carbonate of lime in the sheaths or envelopes of 
the wood, bears a greater proportion to the silex than in our 
common mortar, than which their substance is much harder, for 
it amounted to 43 per cent. There is much ferruginous sand 
with that thus thrown up, resulting from the destruction of the 
masses of red tufa constantly falling from the cliffs into the sea. 
On the western limit of this local deposit are large globules of 
basalt, (which, from their concentric form, and other appear- 
ances, have evidently been in a fluid state), lying loose upon 
the soil, from the tufa (in which they are still found imbedded 
at greater height), having been washed away from them. On 
such a soil the vegetation must be wretched ; a mesembryanthe- 
mum, and an orobus were the only plants that existed, or rather 
languished there. 
Having described this locality to the best of my ability, I 
leave abler geologists to draw the conclusions. But, perhaps, I 
may be allowed to submit, First , That it has evidently been an 
irruption of the sea, from the heaps of terrestrial shells mingled 
with the marine , and from the trees being found standing on 
their roots, and not deposited promiscuously in detached frag- 
ments, or flattened, as they would be, had they been transported 
thither, or had they been subjected to any pressure from a su- 
perincumbent stratum afterwards removed. Secondly , It is, 
clear that this must have happened after the Atlantic had lost 
that considerably higher level which the oysters and marine 
shells, found 300 miles inland, in the Blue Mountains of Ame- 
rica, would seemingly indicate ; for the deposit (extending about 
f ths of a mile in each direction) is bounded by hills and small 
peaks rising several hundred feet above it (composed of the same 
* Specimens of these lignites- will be sent to the Geological Society. 
