Mr. De la Beche on the Geology of Jamaica. 171 



for although we are generally prepared to meet with the same fossils in rocks of 

 an older date, — such for instance as the submedial or transition limestones, — yet 

 in rocks of the tertiary class, which are generally considered as of partial oc- 

 currence, and more regulated by local circumstances, we scarcely expect to 

 meet with fossils of the same species at any great distances, such for instance 

 as that between Paris and Jamaica. Let however the above list of organic 

 remains be compared with that given of those contained in the London Clay 

 by Messrs. Conybeare and Phillips in their " Outlines of the Geology of En- 

 gland and Wales," and with the fossils contained in the Calcaire grossier of 

 Paris enumerated by MM. Cuvier and Brongniart in their account of the 

 beds of the Paris Basin, and the reader cannot fail to be struck with the 

 general resemblance between them as far as respects fossil genera. From 

 this circumstance it might be inferred, that the white limestone of Jamaica 

 belongs to the same epoch of formation as the Calcaire grossier of Paris and 

 the London Clay of England. 



This formation is of considerable depth in several places, particularly in the 

 parishes of Manchester, Clarendon, St. Ann, St. Thomas-in-the-Vale, and St. 

 David ; its thickness in some of these places cannot be less than from 2000 

 to 3000 feet. 



In enumerating the localities of this formation, I shall begin with the parish 

 of Manchester ; because that parish forms the south-western portion of the 

 part of Jamaica which I propose to describe, and moreover the middle of the 

 formation can be well studied among its mountains. 



The road from Mount Pleasant in Clarendon, over the mountains to New 

 Forest near Alligator Pond Bay, presents a great mixture of the compact 

 white limestone with a red sandstone : the latter seldom appears on the sur- 

 face in an undecomposed state, its place being very generally marked by a 

 red marly soil. The mass of these rocks has a southerly dip, where the dense 

 vegetation will permit an examination. On the descent of Plowden Hill 

 towards New Forest, compact white limestone is seen interstratified with 

 rather compact red sandstone, which contains nodules and stripes of the 

 white limestone, evidently of contemporaneous formation with it. The beds 

 are slightly curved, and dip sometimes at 35°, at others at 40° to the S.W. 



The neighbourhood of New Forest, near Alligator Pond Bay, presents sin- 

 gular mixtures of the white limestone with the red sandstone : the most re- 

 markable of these are found among the Plains (as they are called) of St. Eliza- 

 beth's, included between the Santa Cruz Mountains and those of Manchester, 

 and terminating near Alligator Pond Bay. Small patches of rock, rising from 

 ten to twenty feet above the level of the plain, are abundantly scattered over 



