259 
Guppy Reprint 
1 1 1 
Page ng 
1872 part of the “Proceedings of the Scientific Association 
Trinidad,’’ and in the Geological Magazine (1873, p. 62), 
I gave particulars to which I would refer for further eluci- 
dation of the matter. I have onlj’ now to add with re- 
ference to this part of the question that I have not been 
able to explore that part of the coast section at Sanfernan- 
do which lies between the portion shown in my diagram 
in the Geological Society’s Journal (previously referred to) 
and the mouth of the Sipero River, and that I think it likely 
that an exploration of that portion of the section would throw 
some further light upon the relations of the Sanfernando bed s 
(Eocene) and the South Naparima marl (Miocene). 
In my paper published in the “Proceedings of the Scientific 
Association of Trinidad’’ for December, 1877, I gave a diagram 
(fig. 3) to show the general succession of the rocks of Trinidad. 
In engraving this diagram the artist left out several of the letters 
of reference, of which an explanation is given on page 1150! the 
accompanying text. According to the diagram and the explana- 
tion the rock formations of Trinidad are in ascending order as 
follow’s: — 
(a bed) Caribean group (paleozoic). 
(e) Compact limestone ^ Devonian) } 
if) Secondary rocks (Neocomian). 
(jo"! E^ocene of Sanfernando. 
[g') Eocene of Manzanilla. 
(h) Miocene of Guaracara. 
{h') Miocene of South Naparima (including the polycy.stina 
marls. 
(//'■') Miocene of Savaneta, Point Noir, &c. 
{h'") Miocene and Pliocene (mostly the latter, I believe), of 
Moruga, Mayaro, &c. 
(?) Postpliocene. 
The letters omitted by the artist were g, h and //', while 
was written as g. Had the.se errors not been committed, my 
views as to the relative age of the rocks of Trinidad, including 
the Eocene marls of Sanfernando and the Miocene marls of South 
Naparima, would have been clear to any one referring to the dia- 
gram quoted and its explanation. 
In December. 1888, and January, 1889, I corresponded with 
Mr. Juke.s- Browne, then in Barbados. Under date 8th January, 
he asks me ; “Is the P. marl at San F. interbedded with the 
other beds? If not and if the exposure is an i.solated one, is it 
not possible that the marl overlies the Eocene as it does here ? 
In the absence of contained fo.s.sils (except Radiolaria) and in the 
absence of direct evidence, it seems to me that the marl mav be of 
any age later than Eocene.’’ I replied to this, sending Mr. 
Jukes-Browne a copy of m3’ diagram and explanation (fig. % and 
