370 STEVENSON 



The succession at both places is that of thin limestones varying 

 in hardness but with very little trace of shale. No exposures 

 were seen in open fields on the east side, but the harder beds 

 are shown on the schoolhouse hill south from the waterway just 

 mentioned, where the decayed outcrop gives opportunity to see 

 the fossils. 



The toughness of the lower portion is such that fossils can be 

 obtained in very few places ; even where decay has gone on for 

 a long period, the result is little more than mere separation 

 of the lenses, leaving the limestone itself as refractory as before. 

 A few layers, however, are more readily treated and yield nu- 

 merous strophomenoid forms, one of them being evidently the 

 StropJieodonta of the Tentaculite. Sieberella galeata is found 

 abundantly with the valves separate. Uncinulns nmtabilis, At- 

 rypa reticularis are common ; rude fragments of OrtJioceras and 

 pygidia of Dabtianitcs occur, and fragments of crinoidal stems 

 are not rare. In the upper division the same forms are present, 

 but the Sieberella is less common. A layer within two or three 

 feet from the top is characterized by the Lepadocriiuis gebhardi, 

 A continuous outcrop of more than 200 feet in the field south 

 from the schoolhouse shows the stems in great abundance, but 

 complete specimens are very rare, barely a dozen examples 

 having been obtained during almost seventy years of collecting 

 by three generations of Gebhards. This horizon is exposed in 

 the park near Schoharie village. One of the higher layers con- 

 tains great numbers of Mariacrinus stems, some of which are 

 more than a foot long. 



3. The Delthyris or Catskill Shaly Limestone 



The immediate contact between the Lower Pentamerus and 

 the Delthyris was not seen, there being a concealed interval 

 of from two to five feet between characteristic beds. The thick- 

 ness of the Delthyris by barometer is from 85 to 95 feet. The 

 mass is a succession of limestone beds, one to three feet thick 

 separated by beds of calcareous shale varying in like manner. 

 The limestones are bluish to dark gray, some of them very light 

 gray. Many of them are somewhat argillaceous and most of 



