hill: geology of Jamaica. 181 



the occurrence of the NummulincB as characteristic of the otherwise un- 

 fossiliferous lower Miocene and its discovery in Haiti. From his details 

 there can be no doubt that the Post-Cretaceous sequence of Haiti and 

 Jamaica are identical in lithologic and paleontologic character, consisting 

 of Richmond-like shales at the base with Orbitoides passing up into Mont- 

 pelier-like limestones with Orbitoides and Nummulites. In the chapter 

 on "The Geology of the Monte Cristo Range," pages 162-173, he shows 

 that the Orbitoidal White Limestone, as in Cuba and Jamaica, occurs to 

 heights of 2,530 feet. This limestone at Monte Cristo is foraminiferal 

 and of great purity, and like the Montpelier of Jamaica does not weather 

 into red soils. It is also interesting to note that in San Domingo as 

 in Jamaica the NummuUnce and Orbitoides occur in the limestone, and 

 the latter extends down into the shale. 



Tippenhauer has described the white limestones of Haiti more fully 

 than Gabb, but like the latter refers them to a more recent age. Under 

 the head of the " White Limestone " which he says covers five eighths 

 of the island, he describes several varieties which perfectly conform with 

 the descriptions of the Jamaican rocks. Unfortunately, however, he 

 includes the coast limestone or elevated reef rock in this category and 

 assigns the whole to the Post-Pliocene. 



Concerning the Haitian Radiolarian beds nothing is known regarding 

 their stratigraphy, the material being known commercially only from 

 St. Jeremie. From the similarity of geological structure and sequence 

 of that end of the island, and in the absence of information to the con- 

 trary, we can at least infer that the Radiolarian beds of this locality 

 are closely related to those of Cuba and the Montpelier chalks of 

 Jamaica. 



The Radiolarian and Globigerina earths of Barbados have been made 

 the subject of extensive researches by Jukes-Browne and Harrison,^ 

 Gregory, =^ and others, and the geology of this island has been recently 

 thoroughly restudied by the writer. 



The details of this structure are elaborated with great minuteness in 

 the publications of Jukes-Browne and Harrison. With the exception 

 that they referred the Radiolarian earths and the underlying Scotland 

 beds to newer epochs by one stage than that to which I think they 

 belong, their reports are in general correct. 



In Trinidad beds of Radiolarian and Globigerina chalks occupy the 



1 Quart. Jour. Geol. Soc. London, 1892, Vol. XL VIII. p. 193. 



2 Paleontology and Physical Geology of the West Indies. Quart. Jour. Geol. 

 Soc. London, 1895, Vol. LI. p. 293. 



