616  INDEX    TO    PUBLICATIONS    OF    U.    S.    GEOL.    SIRYKY.      [bull.  177. 
Pickens  sandstone  in  West  Virginia GF  34,  p  2 
Picrallumogene,  analysis  of,  from  New  Mexico,  Las  Vegas Bull  78,  p  121 
Picrite-porphyry,  analysis  of,  from  Michigan,  Crystal  Falls  district Mon  xxxvi, 
pp  212,  219;  Bull  168,  p  67 
analyses  of,  from  New  York,  Dewitt Mon  xxxvi,  p  219 ;  Bull  168,  p  38 
Picrolite,  analysis  of,  from  North  Carolina,  Buck  Creek.. Bull  74,  p  63;  Bull  78,  p  15 
analysis  of,  from  New  Jersey,  Montville  (residue  from) Bull  78,  p  18 
Piedmont  Plain,  brief  description  of Ann  19,  n,  pp  11,  16 
Piedmont  Plateau,  general  description  of GF  70,  p  1 
of  Maryland,  pre-Cambrian  rocks  of Ann  16,  i,  p  838 
of  middle  Atlantic  coast,  general  relations  of  granitic  rocks  in.  .Ann  15,  pp  657-684 
remarks  on GF  13,  p  1 
Piedmont  quadrangle,  West  Virginia-Maryland,  geology  of .GF  28 
Piedmont  region  of  middle  Atlantic  slope Ann  7,  pp  548-550 
Piedmontite,  analysis  of,  from  Maryland,  Pine  Mountain Bull  113,  p  111 
thin  section  of,  from  Pennsylvania,  South  Mountain  (in  aporhyolite).  .Bull  136, 
pp  116-117 
Piedra  River,  flow  of,  measurements  of Ann  18,  iv, 
pp  281-283;  Ann  19,  iv,  pp  411-413;  Ann  20,  iv,  pp  59,  402; 
Ann  21,  iv,  pp  298-299;  Bull  140,  pp  197-198;  WS  11,  p  71; 
WS  16,  p  145;  WS  28,  pp  139,  142,  145;  WS  38,  pp  308-309 
Pierre  beds,  southeastern  limit  of,  on  Great  Plains Ann  16,  n,  p  573 
Pierre  clay  in  Nebraska Ann  19,  iv,  pp  736,  759 
Pierre  formation  or  group Bull  82,  pp  211,  229 
in  Colorado Ann  17,  n,  pp  567-569,  571 ; 
Mon  xxvn,  pp  69-70;  Bull  82,  p  191;  GF36,p3;  GF58,  p2 
in  North  Dakota  and  South  Dakota Bull  144,  pp  56-57 
in  Wyoming Bull  119,  pp  23-24 
Pierre  shale  in  Black  Hills Ann  21,  iv,  pp  535-536 
in  Colorado GF  9,  pp  6,  8;  GF  68,  p  2 
in  Montana Bull  139,  p  47;  GF  1,  p  2;  GF  56,  p  3 
in  Nebraska,  southeastern WS  12,  p  20 
in  South  Dakota AVS  34,  p  17 
in  Wyoming GF  30,  p  5;  GF  52,  p  3 
west  of  glacial  Lake  Agassiz Mon  xxv,  pp  86-100 
Piezometry,  investigations  in Ann  14,  i,  pp  153-154 
Pig  iron.     (See  Iron.) 
Pigeon  Point,  Minnesota,  eruptive  and  sedimentary  rocks  on Bull  109 
Pigeon  slate  in  Tennessee  and  North  Carolina  . .  .GF  16,  p  2;  ( iV  20,  p  2;  GF  25,  p  2 
Pikes  Peak,  Colorado,  minerals  from  neighborhood  of Bull  20,  pp  40-73 
Pikes  Peak  district,  Colorado,  bibliography  of GF  7.  p  5 
Pikes  Peak  Forest  Reserve,  Colorado,  boundaries,  timber,  fires,  mining,  etc., 
in Ann  20,  \ ,  \  >] >  3-5,  63-74 
Pikes  Peak  quadrangle,  Colorado,  geology  of GF  7 
Pikeville  quadrangle,  Tennessee,  geology  of GF  21 
Pilarcitos  and  San  Andreas  reservoirs,  California,  discharge  of,  measurements 
of Ann  18,  iv,  ]>  370 
Pilgrim  limestone  in  Montana,  description  and  sections  of Ann  20, 
in,  pp  286,  330,  340,  364,  368;  GF  55,  p  2;  GF  56,  p  2 
Pilinite,  chemical  composition  of Bull  125,  p  98 
Pilling  (J.  C. ),  resignation  of,  from  office  of  chief  clerk Ann  12,  i,  p  19 
PinaceEe  of  Cretaceous  of  Black  Hills Ann  19,  n,  pp  644-645 
of  Mesozoic  of  California Ann  20,  n,  pp  362-363 
of  Mesozoic,  older,  of  North  Carolina Ann  20,  n,  pp  305-310 
