Mr. De la Beche on the Geology of Jamaica. 179 



Stony Hill, compact white limestone, in some places associated with red sand- 

 stone, dips to the S.S. E. On the lower part of the descent from the same 

 hill to the Agua Alta, light coloured marls and sands separate the great body 

 of this formation from the porphyritic conglomerate on which it rests. 



The white limestone is continued but a short distance eastward from Stony 

 Hill : I have however observed a small portion of it resting upon syenite near 

 Somerset estate. 



The Long Mountain situated to the N. E. of Kingston rises principally 

 from beneath diluvial gravel, and is wholly formed of white limestone : the 

 dip is difficult to trace, yet markings may here and there be observed, which 

 would seem to make it probable that it is to the S.W. The most remarkable 

 thing in this mountain is the salt, procured above a pen belonging to Mrs. 

 Clark, sometimes in sufficient quantities to be used at table ; it is found in a 

 small recess, and appears to be derived from the evaporation of saline water 

 which percolates through the marly limestone of the place. 



From the Long Mountain this formation is continued into those of the 

 Port Royal Mountains which approach the sea, and a good section is afforded 

 of its beds up the valley of the Cane River to the Cascade. The white lime- 

 stone is at first observed at the latter place in rather thin beds dipping to the 

 N. E. at a highly inclined angle. Higher up the valley, the beds become 

 thicker and dip to the S.W. at from 75° to 80° : near the falls the beds are al- 

 most perpendicular. From the various inclinations of the strata, they appear 

 to have been much disturbed in this vicinity. 



From the valley of the Cane River, a belt of the white limestone formation, 

 varying in breadth, and separating the older rocks of the interior from the sea, 

 runs round the coast from the South to the North side of the island by the 

 East End, and passes through the parishes of St. David, St. Thomas-in-the- 

 East, Portland, and St. George's. 



The lower part of the valley of the Yallahs River presents a good section 

 of the St. David's portion. Ascending the river from Albion estate, compact 

 white limestone beds are seen near Norris dipping to S.S.E. at about 40^; 

 they will also be observed curved on the face of the cliffs, which for some di- 

 stance up are formed of this rock on both sides the river. Approaching Mount 

 Sinai estate, the lower beds of the formation are exhibited by the road side, 

 and in a great measure correspond with those occurring near Chapelton (Cla- 

 rendon), with the exception that the sands do not seem so abundant, whereas 

 the marls are more so. Among the lower white limestone beds, which are 

 slightly earthy and arenaceous, I found many organic remains, among them 

 echinites (cidaris and spatangus), spines of echinites, ostreae, myae, and 



