POSITIVE AREAS 657 



Page Plate 

 Positive and negative areas 441, 546, 603 



Bearing on paleogeography of 336 



Post-Ordovician oscillations in North America 421 



Potosi dolomite 629, 630 27 



( ?) dolomite, Alabama 634 



formation, Missouri 615 



Potsdam sandstone 443, 528, 643 27 



Pottsville 29 



"Pottsville, Upper" . . 29 



Powell barrier 626 



Prasopora simulatrix and Mesotrypa quebecensis fauna 369 



Prasopora simulatrix bed 525 



Prasopora zone . . 27 



Pre-Cambrian deposits 546 



Pre-Paleozoic periods of diastrophic activity indicated by grada- 



tional criteria 468 



Present and Paleozoic conditions compared. 317 



Primitia 657 



gregaria ? 653 



Princeton sandstone , 476 29 



Principles of classification 574 



Proctor dolomite 631 27 



Productus magnus 594 



Progressive overlap of marine deposits 448, 449 



structure opposed to theory of current scour 373 



Prosser, Upper . . 27 



limestone fauna, Map of 368 



limestone 369, 488 27 



(Lower Galena) 524 



Protarea vetusta 300 



Proterozoic 468 



Protocycloceras 671 



lamarcki 669, 670 



Protowarthia rossi 657 



cf . rossi 674 



Provincial differences in introductory faunal facies 516 



Purdue, A. H., on the Ouachita section 676 



Ptychoparia 493 



Ptyctodus 364 



Pulaski formation . . 27 



Put-in-Bay 28 



Racine dolomite 28 



Rafinesquina alternata 508, 514 



Range in time of fossil species and genera 514 



Raphistoma compressum 661 



Raphistomina sp 664 



Rate of change of faunas 576 



