XVlll. 



TABLE B. 



SUB-DIVISIONS OF THE NEW YORK DEYONIC. 



1. Intawesccns eyioch. 



Neodevoiiian pericxl c. Chemniig group. 



2. Disjunctiis epoch 2. Chemung stage. 



(2). Chemung sandstones and shales. 

 (1). Portage sandstone. 



1. (jenesee stage. 



(3). Naples shales. 

 I (2). Genesee shales, including Stylio- 



I Una limestone. 



I (1). Tnllv limestone. 



h. Mesodevonian period b. Hamilton group. 



2. Spiriteroides epoch 2. Hamilton stage. 



(3). Up])er or Moscow shales. 



(2). Encrinal limestone. 



(1). Lower or Hamilton shales. 



1. M i nil tn epoch 1. Alarcellns stage. 



(1). Marcellus shales. 

 a. Eodevonian period a. Upper Heklerberg group. 



3. Acuwiiuitus epoch 3. Cornil'crous stage. 



(2). Comifjrous limestone. 

 (1). Onondaga limestone. 



2. Caiidagalli epoch 2. Schoharie stage. 



(1). Schoharie grit and Esopus shales. 



1 . Hippnrionyx epoch 1 . Oriskanj- stage. 



(1). Oriskany sandstone. 



The name "' Disjunctiis epoch" (H. S. WilHanis) is derived 

 from the characteristic fossil Spirifer clisjunctus, while the 

 name "'Intumescens epoch" is derived from the characteristic 

 fossil Goniatites hitumescens.^ '' Spirifer oides epoch" and 

 ^^Minata epoch " are derived from the fossils Athyris spiriier- 

 oides and Orhiculoidea niinuta, \vhich are practically con- 

 fined to their respective epochs. The names are of limited 

 applicability.!' In the Eodevonian period, the name ''Acumi- 

 natus epoch" is used for the last epoch, it being derived from 

 the characteristic fossil Spirifer acuniinatus Conrad. This 

 species is represented by ^S. cultrijugatus F. Roemer, in the 

 upper ( Coblenzian ) part of the Rhenan or Lower Devonian 



*See J. M. Clarke, Intumescens fauna, Am. Geol., Vol. VIII., p. 86 et s>eq. 

 tSee note page xvi. 



