CORRELATION OF MODERN DIVISIONS 

 OF UPPER AND MIDDLE LIAS, TABULATED. 



Lower Lias. 



For the sake of utility we here have placed in exact juxtaposition the chief 

 subdivisions of the more recent systematists, in the Upper and Middle Lias. 

 ♦The Tisoa siphonalis of Dumortiee is a problematical fossil found in the Middle 

 Lias of the Rhone frequently, but its nature has not yet been determined. 



