Grabau — Faunas of the Hamilton Group. 



325 



Pteropoda : 



14 Tentaculites gracilistriatus. rc 



15 Styliolina fissurella. rc 



Brachiopoda ; 



74 Orbiculoidea media, r 



77 Schizobolus truncatus. C 



87 Orthotlietes arctostriata. R 



100 Chonetes lepida. r 



115 Spirifer subumbonus. r 



116 Ambocoelia umbonata (small) R 



117 A. prseumbona. C 



121 Athyris spiriferoides. R 

 131 Liorhynchus multicostus. C 

 L. quadricostatus. (?) R 



The relation of this fauna to the normal Spirifer tullius fauna is 

 apparent, differing from this only in the greater development of Schizobolus 

 truncatus and Ambocoelia prceumbona. 



There are, then, a number of quite distinct faunas in the Hamilton group 

 of Western New York. These are : 



F. The Spirifer tullius fauna (including the Schizobolus fauna). 



E. The Spirifer consobrinus fauna. 



D. The Spirifer sculptilis fauna. 



C. The Spirifer mueronatus fauna. 



None of the characteristic Spirifers with the exception of S. mueronatus 

 occurs outside of its proper fauna and this exception is an extremely rare 

 one. 



Underlying these faunas are : 



B The transition fauna of the upper Marcellus. 

 A The Marcellus faunas. 



The " Conodont " bed and its fauna. 



Immediately overlying the limestone layer which contains the Schizobolus 

 fauna at Section H, Eighteen-mile creek, are about two inches of grey shale 



