1922 



CHRONOLOGY 



UlRONOLOGY {continued) 



III IV 



irtian 



V 



Ringsteadian 

 (CCXXV) 



auracian 



Perisphinctean 

 (CCLXXXII) 



)xfordian 



(Argo\4an) 



Argovian 



^ 



-ower Oxfordian 



Divesian 



Cardioceratan 

 (ccxcvi) 



Vertumniceratan 

 (CXVI) 



Kosmoceratan 



(CCLXI) 



Chanasian 



Reineckeian 



3allo\'ian 



Callovian 



Proplanulitan 

 (CCXIII) 



Chanasian 



Macrocephalitan 



(CCLXXXIV) 



