606 PROCEEDINGS OF THE ACADEMY OF [NoV., 



and lying about on the surface, being brought up in every excavation 

 and digging up to, in the region of St. John's, 125 feet above sea level. 

 They are found in some places upon hills to a level of 150 feet above 

 the sea. They are not confined to the Central Plain entirely, for 

 they were seen near St. Mary's Rectory, in the volcanic part of the 

 island, at least 100 feet above sea level. In the vicinity of Willoughby 

 Bay they were seen in the soil of the Central Plain at elevations of 

 upwards of 100 feet also, but they were not noted in the soil upon the 

 high hills near the Montpelier estate in this vicinity. The species 

 were those now living in the sea surrounding the island. They occur 

 in the surface soil, but it cannot be said that there is any very recog- 

 nizable deposit which contains them. As they are in a superficial 

 deposit, this is not to be wondered at; the surface soil everywhere 

 has been disturbed for some depth on account of the cane cultivation, 

 which covers all the available cane-producing land in the island. 

 In some places these marine shells are found associated with recent 

 land shells, as has been described of the raised beaches or horizontal 

 marls of Purves, although these land shells are the species now living 

 in the places where these marine shells occur, and have come into the 

 soil much more recently than the marine shells. During the time 

 of the deposition of these shell deposits the island must have stood 

 at a level of at least 150 feet lower than at present and, in fact, have 

 been divided into two or more islands by the sea, which occupied 

 the Central Plain. Across this plain the sea must have been driven 

 by the trade winds, this wind drift making a current (during the 

 time of greatest depression) running through the Central Plain from 

 Willoughby Bay to St. John's Harbor. The excavating power of 

 this current may have had its part in the formation of these two 

 bays, and of the depressions along the coast from St. John's Harbor 

 north to Corbizon Point, such as Dickenson's Bay. The rise of tide 

 in Antigua is slight, but it must have produced a very appreciable 

 current in this central depression; and during the ebb and flow of 

 the tide, until a channel was established across the inland during the 

 time of sinking, currents due to this cause must have run in and 

 out of the bays. Even during the time of greatest submergence 

 such currents must have been formed and in their flow have had a 

 tendenc}^ to scour the bottom of the bays at either end of the central 

 depression. The currents set up by the tide or (during the time of 

 maximum submergence) by the wind drift would be strong enough 

 to produce the water-worn character observed in the Cassada Garden 

 gravels. And the appearance observed in these materials of having 



