IIG 



NEW YORK STATE MUSEUM 



Rondout two beds filled with heads of Stromatopora occur be- 

 tween 12J and 25J feet below the top of the formation. Asso- 

 ciated with these is a rich gastropod fauna of which a partial 

 list is given by van Ingen and Clark in their report on that 

 region.^ Similar beds are found in the upper part of the Manlius 

 at Becraft mountain, the uppermost of which lies just below 

 the Coeymans limestone. This highest Stromatopora bed was 



Fig. 25 Teiltaculites gyracanthus 



found to contain a modified Oobleskill fauna, with S p i r i f e r 

 e r i e n s i s var. [fig. 19] , S p . c o r a 1 1 i n e n s i s [fig. 20 J 

 and Camarotoechia hudsonica, [fig. 21] , the latter a 

 close relative of C. litchfieldensis, predominating. It 

 is interesting that the first two species are not recorded from 

 the Oobleskill of the Hudson valley, though they are abundant 

 and characteristic of this formation in the Schoharie valley and 

 westward. 



The thickness of the combined Rondout and Manlius forma- 

 tions along the Helderberg escarpment is as follows : Rosendale 

 about 55 ft; Rondout 61^ ft; Becraft mountain 57 ft; New 

 Salem 51^ (6J ft being waterlime at the base) ; Indian ladder 

 51 ft (4J ft of the basal portion belonging to the Rondout); 



^N. Y. state Paleontol. An. Rep't for 1902; N. Y. State Mus. Bnl. 69, 

 p. 1183. 



