224 BULLETIN : MUSEUM OF COMPAKATIVE ZOOLOGY. 



1. The geology and configuration present no evidence whatsoever 

 whereby past land connections can be established between these islands 

 and the North and South American lands in Post-Jurassic time, espe- 

 cially in the Tertiary, Pleistocene, or recent epochs. 



2. The configuration and conditions of these islands in Pre-Jurassic 

 time cannot even be surmised. 



3. There are some hypothetical and biologic reasons for believing 

 that the outer rim of the American Mediterranean constituted a partial 

 or complete bridge between the continents in Jurassic time, and that 

 the Panama bridge did not then exist. 



4. The first definite evidence of Antillean lands is found in the 

 eruptive rocks of late Cretaceous time, when it is probable that there 

 were marine volcanoes. 



5. The land debris constituting the Eocene strata throughout the 

 islands testifies the pre-existence of extensive Cretaceous land areas. 



6. There was a profound regional subsidence in late Eocene and 

 early Oligocene time, which submerged all but the highest tips of 

 the- Antilles, and which extended to the margins of the surrounding 

 continents. 



7. In late Oligocene or Miocene time there was a tremendous ero- 

 genic movement which resulted in uplift, whereby many of the islands 

 were connected with each other, and possibly an insular southern por- 

 tion of Florida, but not establishing land connection with the North and 

 South American continents. 



8. In Miocene or early Pliocene time the islands were severed by 

 submergence into their present outlines and membership, which they 

 have since retained with only secondary modification. 



9. In Pliocene and Pleistocene time there have been intermittent 

 periods of elevation without serious deformation, but not sufficient to 

 establish land connections or to restore the islands to the heights and 

 areas of Mid-Tertiary time. The Pleistocene movements, while epeiro- 

 genic, were sufficiently differential to show that they were not uniform 

 in all parts of the area, showing great diff'erences in amplitude within 

 the West Indian area, and were not harmonious with those of the 

 North American coastal plain. 



10. The irregularities of the submerged configuration of the West 

 Indian region are orogenic, and not due to submerged continental 

 drainage systems. 



11. The elevated coral reefs of the West Indies were formed on 

 rising lands. 



