572 



PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [JuilC 20, 



Fig. 2 is a diagram to show the general relations of the above and 

 other deposits in Trinidad alluded to in this paper. 



Fig. 2. — Diagram Section to show the general Relations of the 

 Formations in Trinidad. 



N.E. Eiver 



Northern Eanges. Caroni 



S.W. 



1. " Caribean Group." 5. 



2. Neocomian. 6. 



3. San Fernando Beds. ] Lower Mio- 7. 



4. " Tamana Series." I cene. 



' Caroni Series." ] jy 



' Moruga Series." / ^PP®^ 



' Detrital Series." 



Miocene. 



The following is a list of the fossils which have been determined 

 from the San Fernando beds : — 



Natica phasianelloides, H Orb. 

 Terebratula Trinitatensis, Guppy. 



cameoides, Guppy. 



lecta, Guppy. 



Grryphsea athyroides, spec. nov. 



Echinolampas ovum-serpentis, Guppy. 

 Spirorbis clymenioides, spec. nov. 

 Ranina porifera,^. Woodw.,s^QG.T\oy. 

 Orbitoides Mantelli, Morton. 

 Cisseis asterisca, spec. nov. 



Besides these fossils there occur species of Pinna, Area, Trochus, 

 Cardita, Lucina, Nummulina, Meter ostegina, &c.* Only one of the 

 Mollusca has been identified with a Miocene species, none with 

 recent species ; and the general affinities of the fossils appear to be 

 Nummulitic. I have for the present retained these beds in the Mio- 

 cene, because they had been so classified by the Geological Survey. 

 Mr. Woodward has been kind enough to determine for me the 

 Ranina, and his note describing the species is appended. It will be 

 seen that the evidence furnished by the Crustacean is in favour of 

 the view I have taken of the age of the San Fernando beds. 



The beds exposed at Manzanilla Point, on the east coast of Trini- 

 dad, consist of a succession of sands, calcareous sandstones, and dark 

 shales. Their stratigraphical relations to the San Fernando beds 

 cannot be ascertained, as they are deposited on the opposite side of 

 the ridge of Neocomian strata. The diagram (fig. 2), in which they 

 are included in the Tamana series, shows their general position ; and 

 I have added a section (fig. 3) to make their stratigraphy more clear. 

 The beds which are seen on the coast at Manzanilla seem to pass on 

 the north under strata assigned by the Geological Survey to the Caroni 

 (Upper Miocene) series; but it is not quite clear whether the pas- 

 sage is conformable or not, owing to the swamps which occur near 

 the junction in the coast section. To the south the extension of the 

 series is hidden by the detrital (post-tertiary) deposits and by the 

 Nariva swamp. The beds may be traced inland for a distance of 

 four miles, when they end abruptly and unconformably on the Neo- 

 comian rocks. As the organic remains collected by the Survey have 

 not been described, I cannot affirm that the deposits classified by 



* Geologist, vol. vii. (1864) p. 160 ; and Quart. Journ. Geol. Soc. vol. xxii. p. 295. 



