Handbook of Paleontology 337 



nearly an east and west direction from Albany county 

 through central and western New York to the Niagara 

 river where it crosses into Ontario, Canada. The sec- 

 ond area occurs in southeastern New York where there 

 are two principal belts running roughly parallel. The 

 beds of the two areas were deposited in different basins 

 separated by a barrier in the Helderberg area which was 

 effective only up to the time of deposition of the Cobles- 

 kill limestone. The western beds were deposited in a 

 part of the interior or Mississippian sea, while the east- 

 ern deposits were laid down in an Atlantic basin. The 

 strata of both the regions have the same color, showing 

 deep red shales indicative of an arid climate. The con- 

 ditions in the eastern basin apparently were not conducive 

 to the deposition of salt and gypsum, but these beds 

 need more exploration. The beds of the western area 

 will be discussed first. Except for the upper waterlime 

 member this group is made up of shales, chiefly red, 

 green and gray, abundantly intercalated with gypsum 

 beds and flaggy dolomites and reaching a total thickness 

 of some thousand feet, more or less. All the workable 

 gypsum deposits of the State are found within the Salina 

 formation, and also the salt deposits. 



The Pitts ford shale (Clarke '03) constitutes the basal 

 Salina series in the western area. It is a bed of black 

 shale of inconsiderable thickness (ten to 20 feet), rest- 

 ing upon the Lockport dolomite, and was separated from 

 the other shales on account of its fauna, mainly euryp- 

 terids. The name is derived from the type exposure at 

 Pittsford, Monroe county, and here interbedded flaggy 

 dolomite occurs. On Grand island in the Niagara river 

 a shale of similar character occurs, but without euryp- 

 terids; and in Herkimer county the shales occur with 



