NATURAL SCIENCES OF PHILADELPHIA. 



423 



1898.] 



" Of the 31 named, 2, Actinoptychus Heliopelta and Aulacodiscus 

 Rogersii are distinctly Miocene ; 4, Coscino discus robustus, Stephano- 

 pyxis aculeata and Corona, and Triceratium semicirculare are quite 



characteristic of that period, while of the remaining 25, onl) r 4, 

 Campy lodiscus Eeheneis, Cerataulus turgidus, Eupodiscas radiatus 



