86 THE NAUTILUS. 



The latter species is significant. It is referred by Dr. Dall to 

 the Miocene of North Carolina, Virginia, Maryland, S. Carolina 

 and New Jersey, and to the Pliocene in Florida, Georgia and S. 

 Carolina. Dr. Dall writes of it (Contributions to the Tertiary 

 Fauna of Florida, 1898); " Area limula is with little doubt the 

 progenitor of A. ponderosa, Say, from which it differs by a more 

 quadrate outline and more anterior beaks. The sculpture is 

 usually more elegant." This species does not survive in the 

 recent molluscan faunas. 



A. (Scapharca) transversa, Say, very familiar to-day along the 

 eastern sea-board of the United States, apparently began its life 

 history in the Pliocene, and in the upper beds of that formation, 

 (Dall): attaining its maximum development perhaps in the Plio- 

 cene also. The determination of the formally correct reference 

 in time of these fossils, which are unquestionably contempor- 

 aneous with each other, is without more evidence uncertain. 

 But assuming as fixed the datum point of A. transversa as some- 

 where in the Pliocene, and allowing weight to the probability of 

 A. limula finishing its career in the Pliocene, an age not later 

 than that formation may be safely predicated for the shells at 

 Southampton. And the deduction seems legitimate that at 

 that day the climatic conditions along the edges of Long Island 

 were more mild than to-day. It is to be hoped that explora- 

 tions in this neighborhood will establish more valuable and ex- 

 tended conclusions. 



In view of the discussions now pertinaciously continued as to 

 the stability of our coast line, it is, in this connection, interest- 

 ing to learn that at Southampton, according to the old records 

 (Pelletreau) the ocean has encroached on the land to an extent 

 of the whole width of the beach, and fence-posts formerly set up 

 back of the "beach banks " (sand dunes) are now down to the 

 level of the water at ordinary high-water mark. These dunes 

 ("beach banks") also retreat before the incessant whipping 

 and pressure of the winds, and deserted whaling boats, formerly 

 abandoned behind them, viz., on their northern slopes, have 

 been overwhelmed and have subsequently re-emerged on the 

 south side of the northwardly shifting sand mounds, whose 

 transgression for a time buried them. 



