4:4 Pelecypods of the Boiuden Fauna [212 



absent, so that it seems probable that Duplin temperature 

 conditions are more nearly duplicated between Cape Fear 

 and Charleston, South Carolina, than along any other sec- 

 tion of the Coast. 



In the succeeding Waccamaw the conditions of the Duplin 

 were some of them intensified but not materially changed. 

 The fauna is, on the whole, more consistent, for both the 

 brackish and the deep water elements are rather less pro- 

 nounced. There were, judging by the abundance of such 

 forms as the. Olivas and Olivellas, extensive sand flats covered 

 by from 2 to 10 fathoms of water, while the wealth of 

 Bittiums and small Cerites and other groups of similar habits 

 demands conditions favorable for extensive algal growth. 

 There is a curious similarity in the general make-up of the 

 Waccamaw and Yorktown faunas, due, doubtless to the 

 similarity in ecology. The Waccamaw waters, however, were 

 decidedly warmer than those of the Yorktown, in fact they 

 were in all probability warmer than at any other period during 

 the middle or late Tertiaries or than those off North Carolina 

 today. The evolution toward the Recent Cape Fear fauna 

 has been marked less by the introduction of a northern 

 element than by the restriction of the more sensitive southern 

 forms to the Floridian province. 



THE PELECYPODS OF THE BOWDEN FAUNA 



By WENDELL P. WOODRING 



1. INTRODUCTION 



The marls exposed along the coast between Morant Bay and 

 Port Morant, near Bowden, almost at the southeastern ex- 

 tremity of the island of Jamaica, have long been known to 

 contain a prolific and splendidly preserved molluscan fauna. 

 In 1862 Mr. Lucas Barrett, the Director of the Jamaican 

 Survey, deposited in the British Museum a collection ap- 

 parently from this locality. A year later Mr. Carrick T. 



