652 E. O. ULRICH INDEX TO ''REVISION OF PALEOZOIC SYSTEMS" 



Page Plate 



Oklahoma formations . . 27, 



28,29 



"Olenidian" 680 



Olentangy shale . . 28 



Olenus 493 



Olenus zone, Age of 678, 679 



Ollenellid trilobites, Origination of 489 



Olenellus 619 



Olenellus fauna 611 



Oneida 28 



Oneonta formation (Oneota in err. ) . . 28 



Oneota dolomite ( Oneonta in err. ) 528, 640 27 



Onondaga formation 303 



limestone . . 28 



transgression 303 



Ophileta 653 



complanata 653, 658, 660, 663 



complanata ? 662 



cf . complanata 664 



? disjuncta 654 



levata 658 



cf . levata 671 



sp 663 



Ordovician . . 27 



Adoption of name 376 



Appalachian Valley 512 



Arctic 494 



Athens trough 538 



Baltic faunas 494 



Chambersburg, Pennsylvania 511 



Changes during 605 



deposits 469 



Disturbances in late 436 



east of Blue Ridge 574 



erosion in Mississippi Valley 308 



faunas 488 



formations. Appalachian Valley 544, 545 



Gulf of Mexico 494 



in caverns 364 



Kentucky 494 



Kentucky and Tennessee 526 



Knoxville trough 538 



limestone, Thickness of 382 



Mercersburg, Pennsylvania 495 



Migration in Appalachian Valley troughs of 544, 545 



Oscillation in (Middle) : 321 



outcrops, Southern Appalachian Valley map showing . . 25 



Progress of classification of 581 



seas, Shifting of 566 



