LIST OF AMERICAN ORDOYICIAN AND SILURIAN FORMATIONS. 



Akron dolomite, Upper Cayugan, New 

 York, etc. 



Albion group or stage, Upper Medinan. 



Albion sandstone, Upper Medinan, New 

 York, etc. 



Alexandrian series, Upper Medinan, Illi- 

 nois and Missouri. 



Alger formation, Clinton, eastern Ken- 

 tucky. 



Allentown limestone, Upper Cambrian or 

 Ozarkian, Pennsylvania. 



Ames Knob formation, Silurian, Maine. 



Amherst feldspathic mica schist, Silu- 

 rian?, New England 



Amherstburg dolomite, Upper Monroan, 

 Michigan and Ontario. 



Amsterdam limestone, Black Biver, New 

 York, etc. 



Anamosa limestone, Cayugan, Illinois 

 and Iowa. 



Anderdon limestone, Upper Monroan, 

 Michigan and Ontario. 



Anticostian series, Silurian, Quebec. 



Aquashicola formation, Silurian, Penn- 

 sylvania. 



Arbuckle limestone, Big Buffalo series, 

 Oklahoma. 



Arisaig series, Silurian, Nova Scotia. 



Arnheim (Warren) formation, Bichmond, 

 Ohio Valley, etc. 



Aroostook limestone, Silurian, Maine. 



Arthrophycus sandstone, Upper Medinan, 

 New York, etc. 



Ashland shale, Silurian, Maine. 



Athens shale, Blount group, Tennessee 

 and Virginia. 



Atkinson. See Fort Atkinson. 



Attalla conglomerate member, Chazyan, 

 Alabama. 



Auburn chert, Black Biver, Missouri. 

 Auroral=Canadian-Black Biver, Penn- 

 sylvania. 

 Austin Brook quartz porphyry, Post Or- 



dovician, New Brunswick. 

 Avondale limestone, Cambrian-Ordovi- 

 cian(?), Pennsylvania. 



Axeman limestone, Canadian, Pennsyl- 

 vania. 



Ay liner formation, Chazyan, Quebec. 



Bainbridge limestone, Niagaran, Mis- 

 souri. 



Bakera limestone (=Brassfield), Upper 

 Medinan, Tennessee. 



Bald Eagle conglomerate, Cincinnatian, 

 Pennsylvania. 



Bald Mountain limestone, Canadian, New 

 York. 



Baltimore gneiss, Ordovician, Pennsyl- 

 vania. 



Barnegat limestone, Cambrian-Ordo- 

 vician, New York. 



Barree group, Silurian, Pennsylvania. 



Bass Island series, Lower Monroan, (Cayu- 

 gan), Michigan, etc. 



Baxters Brook formation, Lower Ordovi- 

 cian, Nova Scotia. 



Bays sandstone, Trenton, East Tennes- 

 see. 



Beauharnois formation, Canadian ^Divi- 

 sion D of Beekmantown), Quebec and 

 Ontario. 



Beaver division, Silurian(?), Texas. 



Beavertown marl (division of Brassfield), 

 Upper Medinan, Ohio. 



Becsie Biver formation, Anticostian, An- 

 ticosti Island, Quebec. 



Beech Hill Cove formation, Niagaran, 

 Nova Scotia. 



Beech Biver formation, Upper Niagaran, 

 west Tennessee. 



Beekmantown (Calciferous) limestone, 

 Canadian, New York, etc. 



Belfast bed (Elkhorn), Bichmond, Ohio 

 Valley. 



Belledune group, Silurian, New Bruns- 

 wick. 



Bellefonte limestone, Canadian, Pennsyl- 

 vania. 



Bellevue member, Maysville, Ohio Val- 

 ley. 



Bellowspipe quartzite, Silurian?, Massa- 

 chusetts. 



1511 



