182 



MESSES. J. B. HAKEISON & A. J. JUKES-EROWNE [May I 899, 



the same age as those of the coast-section, and (3) radiolarian beds 

 similar to those of Barbados. To avoid misconception, I shall 

 speak of the latter two as Oceanic Beds and of the first as the 

 Nariva Beds. 



Wo sections were seen showing the junction of the two formations, 

 but there appeared to me to be abuudant evidence that the two 

 series occupied the relative positions assigned to them by the 

 Geological Surveyors. This is especially clear in the many railway- 

 cuttings through the Ste. Madeleine Estates of the New Colonial 

 Company and also near Princestown (see map, fig, 1). 



The cuttings 



Fig. 



1.- 



-Map of the Naparima District, 



[Scale : 1 inch = about 5 miles.] 



The peology is taken direct from Wall & Sawkins's map ; the topography is 

 traced (by permission) from a new map in the possession of the Colonial 

 Office. 



and the deeper valleys traverse the clays and variegated marls of 

 the Nariva Series, while the hills are capped with the light- 

 coloured Oceanic marls. 



Towards the east, between the Ste. Madeleine Usine and Princes- 

 town, the marls contain rather more argillaceous than calcareous 

 matter, while towards the south-west, from Ste. Madeleine to 

 Hermitage Estate, more calcareous beds are seen passing gradually 

 and laterally into calcareo-siliceous marls ; and, finally, near the 

 outcrop of the deposit above the Oropuche Lagoon, in the neighbour- 

 hood of Cedar Grove and Hermitage, into siliceo-calcareous beds. 



At Princestown, the lower beds, judging from specimens collected 



