280 Dr. J. D. Dana on the Origin of 



J. R. Bartlett, U.S.N., and a consideration of the facts con- 

 nected with the distribution of marine and terrestrial species. 

 As the soundings show, the former of the two connections 

 requires for completeness an elevation of the region amounting 

 to 4060 feet over the part south of Jamaica, 4830 feet between 

 Jamaica and Hayti ? and 5240 feet between Hayti and Cuba. 

 The other line of connection requires an elevation of 3450 

 feet. An open channel, as he observes, would thus be left 

 between Anguilla and the Virgin Islands, where there is now 

 a depth of 6400 feet, The close relations in the existing 

 fauna of the Gulf to that of the Pacific waters prove that it 

 continued to be a salt-water gulf through the era of elevation. 



Mr. Agassiz infers that the connection of the West- India 

 Islands with South America existed before the Quaternary 

 era. But there are other facts which seem to prove that it 

 was continued into, or at least was a fact in, the Quaternary. 



The opinion as to a connection of the Windward Islands 

 with South America in the Quaternary was presented by 

 Prof. E. D. Cope in 1868, and earlier, as he states, by Pomel, 

 on the ground of the discovery in the caves of Anguilla of a 

 species of gigantic Rodent related to the Chinchilla, as large 

 as the Virginia Deer, and nearly equalling the Quaternary 

 Castoroides of Ohio *. Further, De Castro, as cited by Dr. J. 

 Leidy in his c Mammalian Fauna of Dakota and Nebraska,' 

 1869, announced, in 1865, a gigantic Sloth of the " Quater- 

 nary," from Cuba, which he referred to the genus Megalonyx, 

 and Dr. Leidy named Megalocnus rodens, proving a Quater- 

 nary connection between the continent and Cuba. 



The fact of an elevated condition of the region sufficient to 

 make Cuba and Anguilla part of the continent during the 

 earlier Quaternary, if not in the Pliocene also, is thus made 

 quite certain. This is fully recognized by Wallace *!*• Such 

 a condition could hardly have existed without a large elevation 

 also of Florida, though probably not, as Mr. Agassiz holds, to 

 the full amount of the depression between it and Cuba (nearly 

 3000 feet), because Cuba is most closely related in fauna to 

 South America. The subsidence which brought the region to 



• Proc. Philad. Acad. Nat. Sci. 1868, p. 313, and Proc. Philad. Amer. 

 Phil. Soc. 1869, p. 183 ; also ' Smithsonian Contributions to Knowledge/ 

 30 pp., 4to, with 5 plates, Washington, 1883. The last paper (prepared in 

 1878) contains descriptions of the following species from the Anguilla 

 bone-cave : — Amblyrhiza immdata, Cope (the large Rodent announced in 

 1869), A. quadrcMSy Cope, A. latidens, Cope, an Artiodactyl apparently of 

 the Bovidce and a little smaller than Ovis aries. With them was obtained 

 an implement (' 4 a spoon-shaped scraper or chisel ") made of the lip of the 

 large Strombus ffigas, 



T Geograph. Distrib. of Animals, ii. pp. 60, 78. 



