FOR    THE    YEARS    1901-1905,  INCLUSIVE. 
531 
Geologic  formations  described— Continued. 
Pittsburg  limestone,  Carboniferous, 
Maryland,  Clark  and  Martin,  G. 
Pittsburg  limestone,  Carboniferous, 
Pennsylvania,  Clapp,  4. 
Pittsburg  limestone,  Carboniferous, 
Pennsylvania,  Stone  (R.  W.),  7,  8. 
Pittsburg  sandstone,  Carboniferous, 
Pennsylvania,  Stone  (R.  W.),  7,  8. 
Pittsford  shale,  Ontaric,  New  York, 
Clarke,  20. 
Pittsford  shale,  Silurian,  New  York, 
Hartnagel,  1. 
Placita  marl,  Quaternary,  New  Mexico, 
Reagan,  1. 
Platteville  limestone,  Ordovician,  Illi- 
nois, Bain,  11. 
Pleasonton  beds,  Carboniferous,  Kan- 
sas, Wooster,  1.  2. 
Plum  Point  marls,  Miocene,  Maryland, 
Shattuck,  10. 
Pocahontas  formation,  Carboniferous, 
West  Virginia,  Campbell  (M.  R.),  5. 
Pocono  sandstone,  Carboniferous,  Mary- 
land, Prosser,  3. 
Pocono  formation,  Carboniferous,  Mary- 
land, Martin   (G.  C. ) ,  1. 
Pocono  formation,  Carboniferous,  Penn- 
sylvania,  Fuller    (M.   L.),   3. 
Pocono,  Lower  Carboniferous,  Appala- 
chian region,  Stevenson  (J.  J.),  4. 
Pocono  sandstone,  Carboniferous,  Penn- 
sylvania, Campbell   (M.  R.),  6,  8,  18. 
Pocono  formation,  Carboniferous,  Penn- 
sylvania, Butts,  4,  6,  7. 
Pocono  formation,  Carboniferous  (Mis- 
sissippian),  Pennsylvania,  Woolsey, 
3. 
Pocono  formation,  Carboniferous,  Penn- 
sylvania, Stone   (R.  W.),  %  7. 
Pogonip  formation,  Nevada,  Spurr,  6. 
Point  Pleasant  beds,  Ordovician,  Ohio, 
Nicklcs,  3. 
Point  Pleasant  beds,  Ordovician,  Ohio, 
Foerste,  12. 
Poison  Canyon  formation,  Eocene (?)•, 
Colorado,  Hills,  1. 
Pokegama  quartzite,  included  in  Upper 
Huronian  series,  Algonkian,  Minne- 
sota, Leith,  4. 
Polk  Bayou  limestone,  Ordovician,  Mis- 
souri, Adams  (G.  I.),  3. 
Polk  Bayou  limestone,  Ordovician,  Ar- 
kansas, Adams  (G.  I.),  15. 
Polk  Bayou  limestone,  Ordovician,  Ar- 
kansas, Ulrich,  5. 
Portage  formation,  Devonian,  New 
York,  Luther,  2. 
Portage  sandstone,  Devonian,  New 
York,  Clarke,  19,  20. 
Portage  sandstones,  Devonian,  New 
York,  Luther,  1,  2. 
Portage-Chemung  formation,  Devonian, 
Canada,  Corkill,  2. 
Port  Clarence  limestone,  Ordovician, 
Alaska,  Collier,  1,  8. 
Geologic  formations  described — Continued. 
Port  Ewen  limestone,  Devonian,  New 
York,  Van  Ingen  and  Clark,  1. 
Port  Ewen  limestone,  Devonic,  New 
York,  Clarke,  20. 
Port  P]wen  (Kingston)  beds,  Devonian, 
New  York,  Grabau,  9. 
Port  Ewen  beds,  New  York,  Shimer,  5. 
Port  Hudson,  Louisiana,  Veatch,  2. 
Port  Hudson  clays,  Columbia,  Tertiary, 
Louisiana,  Clendenin,  1. 
Port  Hudson  stage,  Quaternary,  Louisi- 
ana, Harris,  2. 
Port  Hudson  clays,  Recent,  Texas, 
Hayes  and  Kennedy,  1. 
Portland  shale,  Devonian,  New  York, 
Clarke,  19,  20. 
Potapaco  member  or  substage,  Eocene, 
Maryland,  included  in  Nanjemoy 
formation  or  stage,  Clark  and  Mar- 
tin, 1. 
Poteau     group,     Carboniferous,     Indian 
Territory  and  Arkansas,  Taff,  4. 
.    Potomac  formation,   Cretaceous,   Atlan- 
tic coast  region,  Darton  and  Keith,  1. 
Potomac  formation,  Cretaceous,  Vir- 
ginia-North Carolina,  Darton,  7. 
Potomac  group.  Cretaceous,  Jurassic, 
Maryland,  Shattuck,  5. 
Potomac  group,  Jurassic  and  Creta- 
ceous, Maryland,  Clark  and  Bibbins, 
o_ 
Potomac  group,  Maryland.  Includes 
Patuxent,  Arundel,  Patapsco,  and 
Raritan  formations,  Clark  and  Bib- 
bins,  1. 
Potomac  group,  Mesozoic,  Maryland, 
Shattuck,  3. 
Potomac  group,  Cretaceous,  Atlantic 
coast  region,  Clark   (W.  B.),  6. 
Potosi  limestone,  Cambrian,  Missouri, 
Keyes,  G. 
Potosi  limestone,  Cambrian,  Missouri, 
Nason,  2. 
Potosi  series,  Cross  (W. ),  1. 
Potosi  limestone,  Cambrian,  Missouri, 
Nason,  5. 
Potosi  series,  Colorado,  Purington,  3. 
Potosi  group,  Cambrian  and  Ordovi- 
cian, Missouri,  Bain  and  Ulrich,  2. 
Potosi  volcanic  series,  Colorado,  Cross 
and  Howe,  1. 
Potsdam  formation,  Cambrian,  New 
York,  Cushing,  2. 
Potsdam  group,  Cambrian,  Illinois,  Al- 
den,  1. 
Potsdam  sandstone,  Cambrian,  Canada, 
Ells,  8. 
Potsdam  sandstone,  Cambrian,  New 
York,  Woodworth,  6. 
Potsdam  formation,  Cambrian,  Wiscon- 
sin, Weidman,  5. 
Potsdam,  Ordovician,  Canada,  Ells,  20. 
Potsdam  sandstone,  Ordovician,  Cana- 
da, Adams  and  LeRoy,  1. 
Potsdam  sandstone,  Cambrian,  New 
York,  Cushing,  9,  10. 
