258 
THE GEOLOGIST. 
of Calcareous Grit), tlie Cornhrash and Forest Marble, and the Fullers' 
Farth, and Inferior Oolite are all left out. 
I could point out many other mistakes ; but I think that the above are 
enough to show that Professor King's Table needs to be a little more 
'•revised and corrected" before it can be said to be "up to the present 
time." I would however remark that the good notion of giving separate 
columns for marine and freshwater types is in great measure marred 
by the formations in one column being printed on the same line with those 
in the other, as if they were exactly of the same age ; whereas such is not 
always the case. Thus, the Eocene Series (in which, by the way, the 
main divisions of Upper, Middle, and Lower are not given) should stand 
as follows, — classing the Hempstead Beds -with it, and not with the 
Miocene : — 
Marine Types. 
Fresh- and Brackish-water Types. 
Upper Eocene . 
Middle Eocene 
Lower Eocene . 
("Parts of the Fluvio-marine series of ") 
Upper Bagshot Sand "j 
Middle f Barton Clay 1 Bagshot 
Bagshot \ Bracklesham Beds f Beds. 
Lower Bagshot Sand J 
London Clay. 
Woolwich and Reading Beds (part of) . 
Thanet Sand. 
a^Sg^B^elMf-" 
Osborne Beds f f ff f w If 
HeadonBeds J Isle of Wight. 
("Shell-beds of Woolwich, etc., 
( Pebble-beds ot Broraley, etc. 
In this form the table shows, at a glance, that there are no purely 
marine formations of Upper Eocene age in Britain ; but that there are 
beds of that age that are mainly of freshwater origin, etc. 
I am, yours truly, 
W. W. 
The Trinidad Fitch Lakes. 
Sir, — I observe in a paper " On the Torbane Mineral Eield," by Mr. 
Taylor, in the February number of the ' Geologist,' a statement to the 
effect that the Pitch Lake of Trinidad stands in close proximity to a vol- 
cano. As this statement has been repeated in various works, and has ap- 
parently led to some false generalizations, it may perha])S be well to make 
the true state of the case a little better known. 
JSTo volcanic substances or erupted rocks have been found to exist near 
the Pitch Lake ; and not only is there no volcano in Trinidad, but, so far 
as I am aware, no traces have been discovered either of ancient or of re- 
cent volcanos in the island. What may perhaps have given rise to the 
statement above alluded to, is the existence of several so-called mud vol- 
canos, or salses, which eject only mud and water, and do not possess a 
temperature above that of the air, and certainly do not appear to have any 
connection with what is usually understood by volcanic action. The neigh- 
bouring parts of South America are equally free from evidences of volcanic 
disturbance. 
What I have stated may suffice to call attention to the subject ; and for 
details, including an excellent and lucid account of the bituminous deposits 
in Trinidad and their probable origin, I would beg to refer those desirous 
of knowing more on the subject to the "Report on the Geology of Tri- 
