184 bulletin: museum of comparative zoology. 



that the medial limestones of my section at the entrance to the great 

 amphitheatre of Matanzas is also of this formation. ^ 



From the numerous paleontological descriptions of Duncan, Gabb, 

 Guppy, and others, this formation is the classical " Miocene " of Haiti and 

 San Domingo, although careful search of the writings of all these 

 authors fails to reveal any stratigraphic data concerning it other than 

 that many of the species came from certain beds near Nivaje. 



There is also reason to believe that the Bowden beds are progressively 

 more shallow in nature from Jamaica towards Haiti. Gabb there 

 encountered this character of formation in contact with the similar 

 appearing Eichmond and Cambridge beds, and confused them together, 

 — a mistake which has been made by nearly all first workers in regions 

 where aggradational terraines of similar composition are in contact with- 

 out a conspicuous intervening deposit. Gabb himself notes the dupli- 

 cation of sedimentation cycles in succeeding epochs^ and these very 

 conditions may have confused him in San Domingo, as they have 

 others in Jamaica. 



It is probable that they may occur in Antigua and other Windward 

 Islands, but exploration has not sufficiently progressed to justify a 

 positive opinion. Beds of Antigua which we consider of a later age 

 than the Bowden beds of Jamaica, and usually discussed with them 

 under the general head of the Miocene by Guppy, Duncan, and others, 

 may prove to be identical with the Bowden. In these islands the vast 

 formations of sedimentary volcanic tufifs were probably being made 

 during this epoch. 



Close studies convince me that these beds are lacking in Barbados, 

 their position being occupied in the latter island by the unconformity 

 between the oceanic (Montpelier) beds and elevated (Pleistocene) reefs 

 during which time land existed there. 



According to Dr. Dall the later or true Miocene is unrepresented in 

 the fossil faunas of the West Indies, during which time the island 

 areas may have had greater expansion than at present. He refers all 

 the formations hitherto called Miocene to the Upper Oligocene. It is 

 my opinion that the differentiation of the faunas of these two epochs 

 needs much research. In Antigua and Porto Eico undoubted Miocene 

 exists. 



Vast aggradational deposits of the Kingston type similarly laid down 

 on pre-eroded troughs, benches, interior basins, or other erosion sur- 



1 Notes on the Geology of the Island of Cuba, Plate I. Fig. 4. 



2 Op. cit., p. 15G. 



