2 PROCEEDINGS OF THE GEOLOGICAL SOCIEXY. [NoV. 9, 



tiary strata has been brought several times before the Society*. All 

 the Corals, moreover, which have been described from the other 

 islands of the Caribbean Sea were derived from strata of a Miocene 

 age. But this communication refers to the Cretaceous and Eocene 

 as well as to the Miocene fauna of Jamaica, and it offers the first 

 palseontological proofs of the existence of the Eocene formation in the 

 West Indian Islands f. 



To do justice to those engaged in the geological survey of Jamaica, 

 it is necessary to bear in mind that there is no good map of the 

 island, no perfect trigonometrical survey, that dense vegetation covers 

 everything, and that the physical difficulties are very great. Hence 

 it has arisen that the geology of the island is still in its infancy. 

 The general features of the country have been determined, and the 

 relations of the series of formations also, but their palaeontology has 

 not been much studied. 



After the publication of Sir H. De la Beche's memoir on Jamaica, 

 little was done for many years in the geology of the island, and the 

 first important communication on it was a diagram of the succession 

 of the strata, which was drawn by the late Mr. Barrett, and which 

 introduced to notice the Cretaceous rocks with their Hippurites, an 

 Acteonella, a Nerinoia, and an Orhitoides. The age of the Cretaceous 

 rocks was suggested by Mr. Barrett, and was confirmed by Dr. S. P. 

 Woodward by the discovery of a shell resembling Acteonella Icevis, 

 D'Orb., and by his admirable paper on the nature of the Barrettia 

 monilifera, Woodw. ; that of the Plant-bearing dark shales above the 

 Hippurite rocks was, from stratigraphical reasons, asserted to be 

 Eocene by Mr. Barrett, whose determination of the Miocene age of the 

 coralliferous sands and shales at the base of the great inclined lime- 

 stone was proved to be correct by those who examined the fossils. 

 The great disturbance of aU the strata, the existence of porphyries 

 beneath the sedimentary rocks, and the association of cupriferous 

 granite with the Tertiary strata have been determined by the survey 

 and noticed in the Quarterly Journal of this Society J. 



2. Notice of the Relations of the Jamaican Strata. 



The original surface of Jamaica appears to have been composed 

 of crystalHne schists ; but they have long since disappeared, and the 

 only traces of such rocks hitherto observed consist of fragments of 

 mica-schist and gneiss, associated with masses of granite, in some 

 of the conglomerates in the neighboui-hood of Port Maria. 



* J. C. Moore, Quart. Journ. Greol. Soc. vol. xix. p. 510. T, E. Jones, 

 Quart. Journ. Greol. Soe. vol. xix. p. 515. L. Barrett, Quart. Journ. Geol. 8oc. 

 vol. xvi. p. 324. P. M. Duncan, Quart. Journ. Geol. Soc. vol. xix. pp. 406, 513 ; 

 vol. XX. pp. 20, 358. See also S. P. Woodward, ' Geologist' for 1863, p. 372. 



t The fossils about to be described by me were collected by Mr. WaU ; and 

 the following notice of the general relations of the Cretaceous, Eocene, and Mio- 

 cene strata is the result of our correspondence. Mr. Wall has furnished the 

 sections and the Map of Clarendon. — P. M. D. 



X J. G. Sawkins, Quart. Journ. Geol. Soc. vol. xix. p. 35. Prof. Owen has 

 described a fossil Mammal from the incKned hmestone (Quart. Journ. Geol. Soc. 

 vol. xi. pp. 532, 541). 



