NAPLES FAUNA IN WESTERN NEW YORK, PART 2 20/ 



the Devonic lakes of Scotland and the Orkney islands, whose existence and 

 geographic details have been demonstrated by Sir A. Geikie. 1 Comparison 

 may also be made with such existing bar-locked lagoons as those which 

 fringe the Baltic coast of East Prussia, the Frisches Haff and the Kurisches 

 Haff. Into each of these opens a considerable drainage, the Vistula and 

 the Niemen, and each is cut off from the marine waters by a long thin bar 

 through which the fresh water normally finds exit at only one narrow 

 opening. At times of storm from without these bars are shifted or broken 

 only to be rebuilt by the natural reaction between the currents of sea and 

 river. With the sporadic breaking down of the barriers the sea fauna is 

 washed into the unpropitious conditions of the lagoon or the lagoon fauna 

 carried out into 'the marine deposits. 



We have shown from the nature of the Styliola limestone and the 

 abundance of pteropods in the still higher strata, the probable existence of 

 warm currents setting into the Appalachian gulf from the southwest, and of 

 colder currents sweeping the coast line eastward to the region of the 

 Oneonta lagoon and presenting to the incoming fresh waters the obstacle 

 necessary to the building of a barrier. 



Nonmarine stages succeeding Lake Oneonta. Probably at no time in 

 the long history of the shallowing of the waters of the gulf was any part 

 of it so nearly cut off from ingress of the sea waters as during this early 

 period of Portage time. During the following epoch (Chemung time) 

 similar conditions continued, but the area of impounded water expanded 

 southwestward by the opening or extension of old barriers. The inter- 

 leaving of its sediments with those of the marine Chemung ahd~even 

 post-Chemung deposits indicates a possibility of easier encroachment of one 



1 The sands of the Scottish Old Red lakes have been shown to be in no inconsider- 

 able part wind blown, and imply arid and desert wastes about the shores of the impounded 

 waters (See the investigations by William Mackie and J. G. Goodchild in the Transac- 

 tions of the Geological Society of Edinburgh for 1897-99). To what extent similar 

 conditions are implied in the composition of the Oneonta and Catskill sands has yet to 

 be determined. 



