112 



FOSSIL ECHINI OF THE WEST INDIES. 



It is worthy of note that every undoubtedly Eocene species in the 

 West Indies is confined to the Eocene. These species, therefore, 

 according to present information, are excellent indicators of strati- 

 graphic position. 



OLIGOCENE. 



The Oligocene in the West Indies comprises two horizons, which are 

 typified by the Antiguan middle Oligocene and the Anguillan upper 

 Oligocene. 1 The Anguillan horizon would be referred to the Miocene 

 by many stratigraphers, because it and equivalent horizons are 

 correlated with the European Aquitanian. 



MIDDLE OLIGOCENE. 



List of species from the West Indian middle (Antiguan) Oligocene. 



1 For discussion, see T. W. Vaughan, U. S. Nat. Mus. Bull. 103, pp. 198-212, 582-586, 1919. 



