142 NEW YORK STATE MUSEUM 



Lower Marcellus shale 



A 4 inches. This is the lowest layer of the Marcellus shales 

 exposed in the section. The rock is a gray calcareous shale 

 breaking irregularly, and characterized by the great abundance 

 of ostracodes, certain layers being thickly covered with them. 

 Styliolina fissurella occurs frequently among the 

 ostracodes, but other fossils are comparatively rare. The follow- 

 ing species were found in this bed: 



Chonetes mucronatus Hall r 1 



Strophalosia truncata (Hall) r 



Liorhynchus limitare (Yanuxem) rr 



Ambocoelia praeumbona Hall rr 



Nuculites nyssa Hall c 



Lunulicardium fragile Hall c 



Modiomorpha subalata (Conrad) r 



Styliolina fissurella (Hall) c 



Orthoceras subulatum Hall rr 



Isochilina (?) fabacea Jones cc 



Primitiopsis punctulifera (Hall) r 



B 4 inches. This bed is a gray extremely fissile shale slightly 

 darker in color than bed A. Fossils are abundant, Chonetes 

 mucronatus, Strophalosia truncata, and Lun- 

 ulicardium fragile being the most common forms, and 

 all about equally numerous. The complete list is as follows: 



Chonetes mucronatus Hall cc 



Strophalosia truncata (Hall) cc 



Liorhynchus limitare (Vanuxem) rr 



Tropidoleptue carinatus Conrad rr 



Ambocoelia nana Grabau r 



Nuculites triqueter Conrad r 



Lunulicardium fragile Hall cc 



Modiomorpha subalata (Conrad) rr 



Styliolina fissurella (Hall) cc 



Orthoceras subulatum Hall rr 



Goniatites ? rr 



Isochilina (?) fabacea Jones rr 



i c, common; cc, very common; r, rare; rr, very rare. 



