LIST OF AMERICAN FORMATIONS. 



1519 



Plum Creek clay, Clinton, eastern Ken- 

 tucky. 



Pogonip limestone, Canadian-Black 

 River, Nevada. 



Pohenagamuk formation, Ordovician, 

 Quebec. 



Point Pleasant limestone, Upper Tren- 

 ton, Ohio and Kentucky. 



Polk Bayou limestone (lower), Black 

 River, Arkansas. 



Polk Bayou limestone (upper), Richmond, 

 Arkansas. 



Polk Creek shale, Cincinnatian, Arkansas. 



Porcupine group, Silurian-Devonian, 

 Alaska. 



Port Clarence limestone, Silurian and 

 Ordovician, Alaska. 



Potosi limestone, Ozarkian, Missouri. 



Potsdam sandstone, Upper Cambrian or 

 Ozarkian, New York and Quebec. 



Poughquag quartzite, Cambrian-Ordovi- 

 cian, Connecticut. 



Powell limestone, Canadian, Arkansas. 



Poxino Island shale, Cayugan, New York, 

 etc. 



Poxino shale. See Poxino Island Shale. 



Prairie du Chien limestone, Ozarkian and 

 Canadian, Iowa and Wisconsin. 



Proctor dolomite, Ozarkian, Missouri. 



Prosser limestone, Trenton, Upper Mis- 

 sissippi Valley. 



Puckmummis schist, Post Ordovician, 

 Alaska. 



Pulaski shale, Cincinnatian, New York 

 and Ontario. 



Put-in-Bay dolomite, Lower Monroan, 

 Ohio and Michigan. 



Quantico slate, Ordovician (?), Virginia. 



Quebec City formation, Trenton, Que- 

 bec. 



Quebec group, Cambrian and Ordovician, 

 of eastern Canada. 



Queenston shale, Richmond, New York 

 and Ontario. 



Quoddy shale, Silurian, Maine. 



Racine dolomite, Niagaran, Wisconsin. 



Rainy Mountain limestone, Ordovician, 

 Oklahoma. 



Raisin River dolomites, Lower Monroan, 

 Michigan. 



Razor Mountain group, PreOrdovician, 

 Alaska. 



Receptaculites limestone (=Kimma- 

 wick), Black River, Missouri. 



Red Mountain limestone, Upper Medinan 



and Clinton, Alabama. 

 Red Warren limestone, Silurian (?), Utah. 

 Reedsville shale, Trenton and Eden, 



Pennsylvania. 

 Rensselaer grit, Silurian or Devonian, 



eastern New York. 



Richmond group of stage, Lower Medinan. 

 Richmondian. See Richmond. 

 Ridley limestone, Stones River, Tennes- 



SCO. 



Riga schist, Ordovician, Massachusetts. 



Robson limestone, Lowest Ordovician, 

 British Columbia and Alberta. 



Rochdale limestone, Cambrian-Ordovi- 

 cian, New York. 



Rochester shale, Upper Clinton, New 

 York, etc. 



Rocklaud formation, Cambrian-Ordovi- 

 cian, Maine. 



Rockland limestone, Mohawkian, central 

 Ontario. 



Rockmart slates (=Athens), Chazyan, 

 Georgia. 



Rockport limestone member, Cambrian- 

 Ordovician, Maine. 



Rockwood formation, Medinan, Tennes- 

 see and Alabama. 



Rogers Gap division of Cynthiana, Tren- 

 ton, Kentucky. 



Romaine formation, Canadian, Mingan 

 Island, Quebec. 



Rosendale water lime, Cayugan, New 

 York. 



Ross Brook formation, Niagaran, Nova 

 Scotia. 



Roubidoux sandstone, Canadian, Mis- 

 souri. 



Rysedorph conglomerate, Trenton, New 

 York. 



Sabula terraue, Silurian, Iowa. 



Saccharoidal sandstone = St. Peter sand- 

 stone. 



St. Clair limestone, Upper Medinan, and 

 Clinton, Arkansas, Oklahoma. 



St. Elizabeth formation. See Elizabeth. 



St. Francois limestone, Cambrian-Ordo- 

 vician, Missouri. 



St. Joseph limestone, Cambro-Ordovician, 

 Missouri. 



St. Lawrence (Meiidota) limestone, Ordo- 

 vician, Minnesota, etc. 



St. Peter sandstone, Big Buffalo serien, 

 Mississippi Valley. 



