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NEW YORK STATE MUSEUM 



The other locahty lies just north of the most apparent line of dis- 

 placement where the strata have lost their contortions. Here were'; 

 obtained ii 



Tretaspis reticulatus 

 Ampyx hastatiis 

 Ptychopyge ulrichi 



Illaenus americanus 

 Pterygometopus cf. intermedius 



It is not safe to infer great difference in age of these associations. 



Vertical strata on north face of Mt Joli. The Murailles in the distance 



Mt Joli then with its 700 feet of calcareous strata represents a| 

 long stretch of Siluric time, and it would appear that the apparent 

 line of main faulting of the southern or lower against the northern 

 or upper mass, marks the disappearance of some interval in the 

 lower elements of the series as indicated. Such departure as there | 

 has been from the vertical position of the strata is in the direction 

 of overthrow so that the lower lean up against the higher strata. 



We shall presently note the paleontologic evidence indicating dis- 

 placement in the vertical mass itself.. 



1 



