323 



Guppy Reprint 



*75 



I could not obtain much information. But Mr. Raspass has late- 

 ly discovered what appears to be the same bed on the Corosal road 

 about eight miles inland from Pointapier. As this is the only 

 deep-water deposit yet discovered to the north of the cretaceous 

 anticline it is of importance as showing that after their deposition 

 in shallow water the cretaceous beds sank to a sufficient depth to 

 allow of the deposition of the Ditrupa-bed, which I should sup- 

 pose was deposited in 200 fathoms of water or thereabouts. The 

 Foraminiferal Fauna contains some species, e.g. Planorbulina 

 larvata Gonatosphaera prolata, Gaudryina pariana, Haplostiche 

 soldanii, Cristelaria aculeata &c. , which are not found in .the 

 Naparima oceanic beds ; while on the other hand some species 

 characteristic of the Naparima beds are not found in the Ditrupa- 

 bed, for example, Nodosaria abysorum. Lagenas and Ratalines 

 also are comparatively rare in the Ditrupa-bed, except Pulv. 

 canariensis which occurs in that bed though not found or very 

 rare in the Naparima beds. (See my paper in the Proceedings 

 of the Field Naturalists' Club 1893. The exposure of this Dit- 

 rupabed discovered by Mr. Raspass is probabl} 7 not much more 

 than a mile from the Spring Vale quarry which yielded the Mio- 

 cene Fossils lately described in the Proceedings of The Society. 

 The significant difference in organic contents between the Dit- 

 rupa-bed and the Nariva beds shows that the Pointapier cre- 



Page 32 



taceous ridge separated the two areas at the time of their deposi- 

 tion, while the comparatively shallow water area of the Nariva 

 beds was marked off from the oceanic beds of Naparima by the 

 great Naparima Anticline. It would be highly interesting to 

 know the exact relations between the Spring Vale bed and the 

 Ditrupabed, for while the former was deposited in water fift} r 

 fathoms deep the Ditrupabed was laid down at a depth probabl}^ 

 of one or two hundred fathoms. It may be observed that every 

 discovery of the kind I have referred to in this paper enlarges 

 our knowledge of the geological structure of the country and in- 

 volves rectification of previous conclusions. 



