116 bulletin: museum of comparative zoology. 



single detail of stratigraphic or geographic location, to the " Miocene," ' 

 in which epoch all the fossils of Jamaica and the West Indies in general, 

 with few exceptions,^ have been placed. In direct conflict with this 

 opinion, another eminent author in the latest paleontologic publication 

 on the island informs us that " No strictly Miocene strata have jet 

 been discriminated in the Antillean region " ^ and refers the group 

 hitherto so called to the upper Oligocene.^ 



Another serious class of mistakes due to ignorance of the strati- 

 graphic sequence has been the promulgation of erroneous deductions 

 alleging the occurrence in the Antilles of certain forms entirely out of 

 the age position which they were known to occupy elsewhere, such as 

 European Lower Chalk corals in the Jamaican Miocene/ of European 

 Cretaceous corals in the Miocene of Haiti,^ and the occurrence of Eocene 

 Nummulites and Orbitoides in the Upper Miocene of Trinidad ' and 

 Miocene of Jamaica.^ The last mentioned class of errors has had a far 

 reaching influence in general paleontologic literature which will require 

 time and patience to correct. 



Another source of confusion was the fact that writers ignored the 

 existence in the island of any Tertiary formations of earlier age than 

 the late Oligocene (Miocene of all authors previous to Dall), a theory 

 which arose from the unfortunate errors of the English writers who 

 confused the Bowden beds of the east near the top with the Yellow 

 Limestone of the western parishes at the base of the Tertiaries 



Still another cause of misunderstanding was ignorance of the fact 

 which has been pointed out for the first time in our chapters on the 

 stratigraphic conditions, that the great sea depths which separated the 

 island from the continent during its earlier epochs of history — late 

 Cretaceous and Eo-Tertiary times — constituted effective barriers to 

 migration to the site of the littoral faunas of the continental borders. 

 Owing to these barrier depths only a few or none of the shallow water 



1 Guppy, On the West Indian Tertiary Fossils, Geol. Mag., Decade IL Vol. I. 

 pp. 404-411, London, 1874. 



2 The two species of Eocene corals from Port Maria and the Kudistes. 



8 DmU, Proc. U. S. National Museum, Washington, 1896, Vol. XIX. pp. 303-305. 



4 Ibid., p. 304. 



5 Duncan, Quart. Jour. Geol. Soc. London, Vol. XXI. p. 12, 1865. 



^ Gahb (Geoloiiy of Santo Domingo, p. 88) infers that these so called Cretaceous 

 corals in the Haitian "Miocene" are found in gravel of Cretaceous do'bris. 



' Proc. Sci. Association of Trinidad, December, 1872. Port of Spain (1873), 

 Geol. Magaziiuv Decade II. Vol. I. p. 21, 1874. and elsewhere. 



8 Duncan, Quart. Jour. Geol. Soc. London, Vol. XIX. p. 463. 



