) 
JouRNAL OF GEOLOGY, V Plate LV, 
> 
Commencement of Eqke. Gomamence: cement or 
2ndépre mors. 
Commencement of 
main pai 
ae (ae r =n ost SoS 
ee a T = — : 
—— — 7 T T zl Sa u u T ae T T === ~ 
at + To : v = eae . 7 et s = 
SS ———s = — y ae 
