r.r 
fauna of molluska, cox-ala. and foraminifera. 
Such depressions are a common feature in 
the earth’s surface and we have some in our 
aeighbohrbood, such as the Gulf of Paria 
already mentioned and of which I have treated 
in several papers, notably in that one entitled 
“ The Growth of Trinidad,” which Mr. Hart 
has so severely criticized in his bulletin. 
Whenever 1 want to have a laugh I turn to 
this criticism of Mr. Hart’s. Nevertheless 
it shows how necessary it is to express 
oneself clearly and to explain fully the 
matter in hand. It is so with my state¬ 
ment of the existence of volcanic dust in 
the oceanic beds of Napaxima. It is not that 
such dust does not exist elsewhere, but that 
it is masked by the much large quantities of 
sand and gravel in which it is disseminated. 
In the oceanic beds the calcai’eous mud in 
which such dust occurs is easily washed 
away, leaving only the heavier material, in¬ 
cluding particles of volcanic dust among the 
residue. Mr. Hart informed me when dis¬ 
cussing this subject that he had evidence 
that Trinidad was never joined to Venezuela. 
I strongly urged him to bring forward this 
evidence which would, whether conclusive or 
not, be highly interesting and might 
elucidate some points in the geological 
history of the islaud. I may here 
refer to the existence not far from 
us of another line of terrestrial weakness 
which in some respects resembles that I 
have mentioned in the north part of Haiti. 
It is that depression in which occurs the 
Gulf of Cum ana or Cameo and which may 
extend on the east to the Gulf of Paria 
and on the west to Caracas, and it may pos 
sibly be one with that depression which is 
marked by the Lake of Valencia. And the 
lossiliferous and lignitiferous beds of Cumana 
and its neighbourhood ai'e probably a con¬ 
tinuation of the tertiary series of Lrinidad 
(called Caroni series in the geological report 
1800;. Further, I suspect that the area 
about Cumana marked on Wall’s map of \ ene- 
zuela as cretaceous includes tertiary as well 
as cretaceous rocks. I have a series ol well- 
marked cretaceous fossils from that locality 
besides the completely distinct tertiary fos¬ 
sils described in the Journal of the Geological 
Society I860. Many of these tertiary fossils 
are of the same species ns those known from 
Haiti and Cumana. Further, I think that 
the legion about Cumana presents a remark¬ 
able geological resemblance to Lavega de 
Santiago in Haiti. It can scai’cely be said 
that landshells are abundant in any part of 
the counti’y we are supposed to be Lavers- 
