GEOLOGY AND PALEONTOLOGY OF THE SCHOHARIE VALLEY 311 



Holopea elongata Hall 

 Laevidentaliuni */>. ? 

 Spirifer vanuxemi Hall v 

 Leperditia alta Conrad c 

 Holopea antiqua (Vantcxem) 

 Zaphrentis sp. ? 



Bed IT is a veritable Stromatopora reef. Bed 18 

 contains in the lower part the following fauna : 



Spirifer vaimxemi Hall c 

 Tentaculites gyracanthus (Eaton) c 

 Stropheodonta varistriata Conrad c 

 Leperditia alta Conrad c 



Ostraeocls, numerous specimens of two or three species 

 Hormotoma, small species 

 Holopea elongata Hall 



Both faunas, above and below the Stromatopora bed 

 are specially characterized by the occurrence of 

 gastropods. 



Feet 



Rondout 20-31 



Chietiy lime mudrocks, mostly unfossiliferous. and 

 containing beds of workable cement. At Rondout 

 the following subdivision has been made by van 

 Ingen and Clark : 



Feet Inches 



Upper with gray cement 

 beds 19 feet, 6 inches 



'11 Paving block or mud crack 3 8 



10 Prismatic or five point 4 4 



9 Leperditia bed 2 1 



8 Curly, variable 8-19 



7 Soft gray cement 3 3 



6 Hard gray cement 5 



5a Middle ledge 7 



Lower or dark cement beds ( 5 Hard black cement 4 8 



9 feet, 7 inches to 11 feet, \ 4 Soft black cement 4 5 



2 inches 3 Footled°re 6" to 2 



Hartnagel and van Ingen and Clark have suggested that the 

 upper beds (6-11) alone represented the Rondout and that the 

 lower beds 3-5, represented the Rosendale cement beds, the seven 

 inch middle ledge (5a) representing the Cobleskill. I believe 

 however that the whole scries here represents the Rondout and 

 that the underlying 5-7 feet of " Coralline limestone'' which rests 

 directly on the upturned Hudson river sandstones in this region, 

 is the Cobleskill, while the Rosendale cement bed ami the Wilbur 

 limestone are absent altogether. Both of these appear at the 

 Wilbur bridge seel ion and south of Wilbur, where the Cobleskill 

 is 10-15 feet thick, which thickness it retains ;ts far as Rosendale 

 or beyond. The Rondout cement above it is 1!) feet thick at the 

 Wilbur bridge exclusive of the mud crack layer or five point bed. 

 At Eddyville the same bed is 7 feet thick exclusive of the five 

 point, the Cobleskill being 10 feet. 



