204 NEW YORK STATE MUSEUM 



Styliola limestone, distinguished from the living Styliola only, so far as 

 evidence goes, etymologically. 1 



Species of recent Styliola occur in immense abundance in the warm 

 Atlantic currents, but the cold northern waters keep them from the coast of 

 Britain. 2 



In these facts we find a rational ground for inferring that the 

 pteropod ooze represented by the Styliola limestone, and the free dis- 

 semination of Styliola in the overlying Naples beds in association with 

 Hyolithus and myriads of the minute spiral and probably pteropodous shell 

 Protospirialis, indicates the presence of swarms of these creatures swept 

 through the upper waters by warm currents coming in from the southwest. 

 The pteropod deposits do not extend in mass eastward of Seneca lake nor 

 do they approach the eastern shore line of this period. Their dissemina- 

 tion in this direction was doubtless prevented by the cold coastal current 

 entering the gulf from the northwest and laving the northern and eastern 

 shore lines. 



The origin of the sediment which constitutes the bands of bituminous 

 shale in the gulf deposits of this time is, in our judgment, to be sought less 

 in the impregnation of the sediments by admixture of organic constituents 

 resulting from decomposition, than in the influx of drainage from low, flat, 

 continental and insular land masses of the southwest or from the deep but 

 swamp filled valleys of Appalachia. This supposition assumes that the 

 organic intermixture was largely terrestrial. 



Here too we may note the gradual introduction in Portage time of a 

 coastal change to the east which became of increasing and widespread 

 importance as time passed on and into the subsequent, or Chemung epoch. 



The apex of the Appalachian gulf during the earlier part of Portage 

 time, must have reached to Albany, the northern shore approximately 



'The zoologist Pelseneer has suggested that the pteropods are a race of comparatively 

 recent development in the earth's history, an opinion for which a restricted acquaintance 

 with the facts of paleontology would seem to be responsible. 



2 Thomson, W. The Atlantic. 1878. p. 127. 



