50 



Trans. Acad. Sci. of St. Louis. 



Trenton Period 



PORIFERA, COELENTERATA 

 AND BrYOZOA 



Hindia parva? Ulrich 



Streptelasma corniculum? Hall 

 Lichenaria typa? W. and S. . 

 Rhinodictya sp. undet 



Brachiopoda 



Dalmanella subaequata Conrad . . 

 Dalmanella testudinaria Dalman. 



hingula sp. undet 



Orthis tricenaria Conrad 



Strophomena incurvata Sheppard 



Zygospira recunnrostra Hall 



Zygospira yiicoUeti W. and S. . . . 



Pelecypoda 



Ctenodonta auhurnensis n. sp 



Ctenodonta costata n. sp 



Ctenodonta mediaHs Ulrich 



Ctenodonta nasuta Hall 



Ctenodonta ovijormis Ulrich 



Ctenodonta n. sp 



Cyrtodonta blllingsi Ulrich 



Cyrtodonta sp. undet 



Goniophora carinata Conrad 



Modiolodon subrhomboideus n. sp. 



Modiolopsis expansa n. sp 



Modiolopsis sp. undet 



Pai-allelodus obliquusn. gen. and sp 



Psiloconcha? sp. undet 



Rhytima sp. undet 



Sphenolium sp. undet 



Whiteavesia subcarinata Ulrich... . 



Gastropoda 



Archinacella patelliformis Hall. . 



Archinacella sp. undet 



Carinaropsis actua U. and S 



Carinaropsis phaleria Sardeson. . 

 Cataschisma typa n. gen. and sp . 

 Conradella fimbriata U. and S. . . 

 Cyrtolites retrorsus Ulrich 



tf 



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o o« 

 a o 



Hudson 

 River 

 Period 



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o o 





03 



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a 



3 



P^ 



P^ 



o3 



o 



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BR 



SBT 

 SBT 

 SBT 



S 

 TH 



SB 



S 

 ST 



SB 



BtoH 



T 



T 

 T 



BT 

 B-H 



BT 

 BT 

 BT 



BT 



TU 



