ANCIENT ANTILLEAN CONTINENT 293 



emerged at the beginning of the Tertiary Era, and must then 

 have been joined by land with Mexico. Some time during 

 the Oligocene Period Professor Schuchert again records a 

 complete submergence of all the West Indian islands except 

 the Bahamas. But such ancient types as Typhlops; Soleno- 

 don and many others, could not have been destroyed. We 

 might suppose that they took refuge on the Bahamas, and 

 thus repopulated the other islands subsequently. Such a 

 theory, however, is exceedingly unlikely. A much more pro- 

 bable explanation is that the Antilles were reduced to small 

 islands, and retained their old animals and plants. In early 

 Miocene times all the Greater Antilles were certainly raised 

 above the sea, and must have been then connected with one 

 another. Jamaica was joined to Guatemala, and Cuba to 

 Mexico, but Jamaica must have separated early from Haiti. 

 While the islands were joined to one another, an interming- 

 ling of the more active ancient types occurred, the less pro- 

 gressive ones being forced to the higher altitudes by the new 

 arrivals from Mexico and Central America. During the whole 

 of Miocene times Yucatan was apparently below sea-level. 

 When it rose in the Pliocene Period, it may have had a short 

 land connection with the Antilles by way of western Cuba. 

 An opportunity was then afforded the mammals of South 

 Americaji type like Amblyrhiza, Megalocnus, and others to 

 spread to the islands. The smaller West Indian mammals 

 came earlier. Central America, during the existence of this 

 Yucatan laad bridge, may still have been separated from 

 North and South America. At this time the Lesser Antilles 

 probably had an independent land connection with Venezuela ; 

 but that there was an Antillean Continent connected with the 

 mainland in Pleistocene times, as suggested by Dr. Spencer, 

 when Central America had already been invaded by the North 

 and South American immigrants, is entirely opposed to the 

 results derived from' a study of the fauna and flora. 



As for the trans-Atlantic land bridge, we cannot assume 

 that it oscillated up and down like the Antillean area, where 

 peculiar local conditions produced exceptional changes of land 

 and water. Some time during the Eocene Period it must 

 have enabled European types to travel right across the 

 Antilles and whatever portions of Central America then 



