340 New York State Museum 



below the Bertie, but in Madison and Onondaga coun- 

 ties the main deposits are directly under the Bertie. On 

 the west these beds continue into Ontario ; east of Madi- 

 son county the Camillus shale thins rapidly, though it 

 extends into Herkimer and Otsego counties. The Bray- 

 man shale which occurs in the east in Albany and 

 Schoharie counties and has been correlated with the 

 Camillus shales will be discussed below (page 341). The 

 Camillus shales are practically barren of fossils. A 

 pelecypod, Ctenodonta salincnsis, has been described 

 (Ruedemann '25) from these beds (Madison county). 



The Bertie waterlime (Chapman '64) was named from 

 the type section at Bertie, Canada, about six miles west 

 of Buffalo. It is a series of drab or gray, argillaceous, 

 more or less silicious dolomites which in years past were 

 quarried on a wide scale for the manufacture of port- 

 land cement. In New York it occurs as far east as 

 Otsego county where it has a thickness of ten feet or less. 

 The maximum thickness of 60 feet is found in Ontario 

 county, and it is 50 to 60 feet thick in Erie county. Be- 

 sides the eurypterid fossils the Bertie waterlime is char- 

 acterized by hopper-shaped casts and impressions which 

 represent salt crystals derived from the salt originally de- 

 posited in the limestone and since dissolved away. The 

 fauna of the Bertie waterlime derives its interest and 

 importance from the prevailing eurypterid content. It 

 is the upper horizon of abundant eurypterids, the Pitts- 

 ford shale representing the lower. Characteristic euryp- 

 terids are Eurypterus lacustris, E. remipes, Eusarcus 

 scorpionis, Pterygotus buffaloensis and DoKchopterus 

 macrochirus. The number of species for the Bertie 

 waterlime has been considerably increased in the past ten 



