282 PEOCEEDINGS 0¥ THE GEOLOGICAL SOCIETY. [Feb. 21, 



In the paper by Dr. Duncan and Mr. Wall, before cited, the rela- 

 tions of the various strata are so well and succinctly described, that 

 it is unnecessary for me to do more in this place than to allude to 

 the fact that the formation whence the mollusca to be described were 

 derived consists of shales, sands, and marls exposed in several parts 

 of Jamaica, and that it has suffered great disturbance, in common 

 with the Tertiary strata of other parts of the West Indies, and is 

 frequently found in a position approaching to the vertical. The 

 identity of many of the species found in these rocks with forms from 

 San Domingo, Cuba, Cumana, Antigua, Anguilla, and Trinidad, shows, 

 the very extended development of Miocene formations in the Caribean 

 area. The period appears to have been one of exuberant develop- 

 ment of marine life, and the conditions seem on the whole to have 

 been favourable to the preservation of the shells and other. remains. 



The general remarks made by Mr. Carrick Moore in his papers on 

 the San Domingan Tertiary fossils * are as a rule applicable to those 

 of Jamaica ; and many of those observations have been confirmed by 

 Dr. Duncan's investigations of the corals, and those of Prof. Eupert 

 Jones of the E,hizopoda. Among the new facts brought to light is 

 the very remarkable resemblance of a portion of the West Indian 

 Miocene fauna to that of the Maltese beds. 



The great difference between the Miocene faunas of the American 

 and Caribean areas is particularly remarkable when we take into 

 consideration the alHances of the latter with the European Mid-ter- 

 tiaries, and the more we investigate the subject, the more we find to 

 confirm the conclusions already arrived at on this head. Still, there 

 is a certain amount of resemblance, and, upon examination, I find 

 that the Petaloconchus Domingensis of Sowerby, appears identical with 

 P. scul^turatus of Lea, from the Miocene of Virginia. 



From my examination of the Jamaican fossils, I am of opinion 

 that, with the Middle Tertiary beds of San Domingo and Cuba, those 

 of Cumana, and the Caroni series in Trinidad, the Miocene of Jamaica 

 is to be considered as representing the upper or later part of the 

 West Indian Miocene as at present known ; while the Chert-forma- 

 tion in Antigua, the Anguilla beds, and the beds exposed at San 

 Fernando in Trinidad, belong to the lower and older part of the 

 Miocene. 



In Jamaica the Miocene strata consist of highly inclined marls 

 and shales, which are especially characterized by Conus, Stromhi, 

 and large Pleurotomce, with small Nummulinm and Orhitoides, as well 

 as corals. At Cumana we have a fauna almost identical with that 

 of Jamaica, including similar foraminifera and corals ; among the 

 latter is Flabellum exaratum, Dune. The beds consist in part of 



Jamaica is very interesting, though I have not been able to separate it into Sir 

 Charles Lyell's divisions. I must first study the recent shells of Jamaica. The 

 newer Tertiary strata contain a Terehratula (with a short loop) a Terebratulina 

 (like caput-serpentis) and an Argiope. There is a marl-bed, probably formed in 

 the deep sea, containing abundance of Pteropods {Cleodora, Creseis, Cuvieria).''^ 

 — ' Critic,' February 1, 1863. 



^'^ Quart. Journ. Geol. Soc. vol. vi. p. 39, and vol. ix. p. 129. 



