hill: geology of JAMAICA. 125 



scribes them as " Orbitoidal limestones, which agree with the descrip- 

 tions of the Claiborne beds by Sir Charles Lyell and Mr. Dana."^ In 

 two other places he referred them to the Mid-Tertiary period, on strati- 

 graphic grounds, because they occurred between the Eocene (our 

 Richmond beds) and the White Limestone, the latter of which he (Saw- 

 kins) erroneously considered Pliocene.^ These original opinions on the 

 part of the field workers to the effect that the beds wera Eocene were 

 abandoned by the authors of the Summaries of the Jamaican Reports, 

 who, writing in England, confused the identity of the (Cambridge) Yel- 

 low Limestone underlying the great White Limestone Series (Montpelier 

 and Moneague formations) with the Bowden Oligocene beds overlying it, 

 and erroneously supposed the latter to be the base instead of the top of 

 the White Limestones. In this manner the identity of the Cambridge Eo- 

 cene faunas was confused with that of the Oligocene, and the age of the 

 whole Jamaican sequence above the Richmond so jumbled that it has 

 become impossible to obtain a correct knowledge of it from the literature 

 concerning the island, even that of the most recent writers, like Jukes- 

 Browne and Harrison, who have said that the upper division of the Mio- 

 cene 'Ms doubtless the true place of the Jamaican Yellow Limestone." ^ 



So confusing has the literature become that of late years there has 

 been a tendency to deny that the rocks of the Eocene were present in 

 the West Indies. The most recent summary of these formations^ omits 

 it in this region with the doubtful exception of the Manzanilla beds of 

 Trinidad. One gratifying result of our researches is the presentation of 

 additional proof that the Eocene period is represented in Jamaica, not 

 alone by the doubtful Richmond beds, but also by the Cambridge forma- 

 tion, and that these collectively constitute one of the most distinctive 

 and important formations, not only of this island, but of all the great 

 Antilles, Barbados, Trinidad, and perhaps the Windward Islands, as 

 will be shown in later pages. 



The Richmond Beds. 



In the Richmond beds animal remains are exceedingly rare. A 

 Natica, a Turritella, and what is probably a large Scalaria associated 

 with two doubtful species of supposedly Eocene corals described by 

 Duncan, have been found in the conglomerate of Point Haldane, at 



1 Jamaican Reports, p. 224. 2 i^id., pp. 130, 138. 



8 Quart. Jour. Geol. Soc. London, Vol. XL VII. pp. 197, 242. 

 4 Dall, " Descriptions of Tertiary Fossils from the Antillean Region." Proc. 

 U. S. National Museum, Vol. XIX. pp. 303, 305. Washington, 1896. 



