376 C. R. STAUFFER ORISKANY SANDSTONE OP ONTARIO 



increases at the expense of the sand and gradually the top of the stratum 

 becomes entirely lime." ^^ This stratum of sandstone and arenaceous 

 material carries an Onondaga fauna and forms the basal layers of that 

 formation. It rests directly on a sandstone which contains the charac- 

 teristic Oriskany fossils. The stratigraphical evidences of unconformity 

 in this case are apparently wanting, but the Paleontological evidences 

 are rather marked. And thus it appears that the conditions which pre- 

 vailed in Ontario during early Middle Devonian were identical with 

 those which existed in portions of J^ew York at the same time, and the 

 "Decewsville formation," ^^ in Avhich the mingled Oriskany and Onon- 

 daga fauna has been supposed to occur, is not an independent unit. 



10 C. J. Hares : Letter of February 9, 1912. 



" E. O. Ulrich and Charles Schuchert : Loc. cit., p. 653. 



