Vol. 51.] AND PHYSICAL GEOLOGY OF THE WEST INDIES. 305 



be correct, then the Loup Fork Beds must be Pliocene. Its fauna 

 however, has such Miocene affinities that Scott suggests that the 

 isthmus must have emerged before the end of this period. There 

 does not seem to be any reliable evidence to put against that of the 

 Loup Fork mammalia. Neither Gabb nor Dall have recorded the 

 names of the Miocene species from the higher levels of Panama, 

 nor did they state what division of the Miocene the fossils indicated. 

 It is therefore probable that the waterway across Central America 

 was finally closed in the Lower Miocene, or possibly even in the 

 Upper Oligocene. 



The Date of ' Aniillia? — A further complication remains to be 

 considered. It is not at all certain that when the Isthmus of Panama 

 was submerged there was a free communication between the 

 Atlantic and the Pacific Oceans. The Caribbean Sea may then have 

 been a gulf from the Pacific, separated from the Atlantic by the 

 land area of the hypothetical ' Antillia.' That there was once a 

 connexion between North and South America along the chain of 

 the Windward Islands, Cuba, the Bahamas, and Florida is not 

 improbable. Evidence for this, either in whole or part, has been 

 advanced by De Castro, Cope, Leidy, and others, whose arguments 

 have recently been well summarized by Sir Henry Howorth. 1 

 Further evidence could be adduced from the study of the land- 

 shells, 2 and also from the remarkable distribution of the species or 

 varieties — whichever they be — of Peripatus. That Cuba was once 

 •connected with Yucatan and Florida is almost certain : that this 

 connexion was in existence in the Pliocene, and probably also in the 

 Pleistocene, is shown by the evidence collected by De Castro. 3 That 

 the area of the Windward Islands was occupied by land in the 

 Lower Kainozoic is also most probable. But this was all submerged 

 at the period when the Oceanic Deposits of Barbados were laid 

 down. There is no adequate evidence to show that at any time 

 after this was there more land in this region than there is at 

 present. The evidence of the Arcliceopneustes -limestone which over- 

 lies the Oceanic Deposits, and of the series of raised reefs, tends to 

 show that Barbados has been undergoing a long, steady upheaval 

 since the period of the great submergence. The rarity of mammals 

 on these islands shows that they have not been part of a continuous 

 tract of land since they rose above the sea : as contended by Prof. 

 A. Agassiz, 4 the islands probably have always been isolated, and 



1 ' The Mammoth and the Flood,' 1887, pp. 360-366. 



2 Thomas Bland, 'On the Geographical Distribution of the Genera and 

 Species of'.Land Shells of the West Indian Islands : with a Catalogue of the 

 Species of each Island,' Ann. Lye. Nat. Hist. New York, vol. vii. (1862) pp. 335- 

 36l ; ' Additional Notes on the Geographical Distribution of Land Shells in 

 the West Indies,' ibid. vol. ix. (1870) pp. 238-241. 



3 M. F. de Castro, ' Pruebas Paleontologicas de que la Isla de Cuba ha 

 estado unida al continente Americano, y breve idea de su constitucion geologica,' 

 Bol, Com. Mapa geol. Espana, vol. viii. (1881) pp. 357-372. 



4 A. Agassiz, ' Three Cruises of the ' Blake ',' Bull. Mus. Comp. Zool. Harvard, 

 vol. xiv. (1888) p. 116. 



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