712  PRE-CAMBRIAN    GEOLOGY   OF    NORTH   AMERICA. 
vey  Pennsylvania,  Harrisburg,  1840,  pp.  252.  Fifth  Ann.  Rept.  Geol.  Explora- 
tion of  Pennsylvania,  Harrisburg,  1841,  pp.  179.  Classification  of  the  meta- 
morphic  strata  of  the  Atlantic  slope  of  the  Middle  and  Southern  States.  Proc. 
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4  Bowlders  of  hornblendic  rock  in  gneiss  near  Philadelphia,  by  A.  R.  Leeds. 
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5  Report  of  progress  in  the  district  of  York  and  Adams  counties,  by  Persifor 
Frazer,  jr.  Second  Geol.  Survey  Pennsylvania,  vol.  C,  1876,  pp.  198,  with  maps 
and  cross  sections. 
6  Report  of  progress  in  the  counties  of  York,  Adams,  Cumberland,  and  Frank- 
lin, by  Persifor  Frazer,  jr.  Idem,  vol.  CC,  1877,  pp.  201^00,  with  maps  and 
cross  sections. 
7  Geology  of  eastern  Pennsylvania,  by  T.  Sterry  Hunt.  Proc.  Am.  Assoc.  Adv. 
Sci.,  25th  meeting,  1877,  pp.  208-212. 
8  The  brown  hematite  deposits  of  Lehigh  County,  by  Frederick  Prime,  jr. 
Second  Geol.  Survey  Pennsylvania,  vol.  DD,  1878,  pp.  99,  with  two  maps. 
9  The  geology  of  Lancaster  County,  by  Persifor  Frazer,  jr.  Idem,  vol.  CCC, 
1880,  pp.  350,  with  an  atlas  of  11  plates  and  maps. 
10  On  the  Hudson  River  age  of  the  Peach  Bottom  slates  and  its  bearing  on 
the  geology  of  southeastern  Pennsylvania,  by  Persifor  Frazer,  jr.  Proc.  Am. 
Philos.  Soc,  vol.  18,  1880,  pp.  366-368. 
11  The  geology  of  Philadelphia  County  and  of  the  southern  parts  of  Mont- 
gomery and  Bucks,  by  Charles  E.  Hall.  Second  Geol.  Survey  Pennsylvania,  vol. 
C6,  1881,  pp.  145,  with  map  and  plate. 
12  The  geology  of  Lehigh  and  Northampton  counties,  by  J.  P.  Lesley.  Idem, 
vol.  D3,  pt.  i,  1883,  pp.  1-82,  2  maps. 
1-5  Itinerary  note  on  the  South  Mountain  gneiss,  by  Charles  E.  Hall.  Idem, 
vol.  D3,  pt.  i,  1SS3,  pp.  215-258.      • 
"The  geology  of  South  Mountain  belt  of  Berks  County,  E.  V.  d'Invilliers. 
Idem,  vol.  D3,  pt.  2,  1883,  pp.  441,  with  6  maps. 
15  Field  notes  in  Delaware  County,  by  Charles  E.  Hall.  Idem,  vol.  C5,  pt.  1, 
1885,  pp.  128,  with  a  colored  map. 
1GA  study  of  one  point  in  the  Archean-Paleozoic  contact  line  in  southeastern 
Pennsylvania,  by  Persifor  Frazer.  Proc.  Am.  Assoc.  Adv.  Sci.,  33d  meeting, 
3884,  pp.  394-396,  with  map. 
17  General  notes ;  sketch  on  the  geology  of  York  County,  Pa.,  by  Persifor 
Frazer.     Proc.  Am.  Philos.  Soc,  vol.  23,  1886,  pp.  391-410,  with  a  map. 
18  A  discussion  on  the  rocks  of  Pennsylvania  and  New  York,  by  Theodore  D. 
Rand.     Trans.  New  York  Acad.  Sci.,  vol.  8,  1889,  pp.  47-51. 
19  The  Laurentian  and  Huronian  formations,  by  J.  P.  Lesley,  in  a  summary 
description  of  the  'geology  of  Pennsylvania,  vol.  1.  Rept.  Pennsylvania  Geol. 
Survey,  1892,  pp.  53-164. 
20  The  ancient  volcanic  rocks  of  South  Mountain,  Pa.,  by  Florence  Bascom. 
Bull.  U.  S.  Geol.  Survey  No.  136,  1896,  pp.  124,  with  geological  map. 
21  Piedmont  district  of  Pennsylvania,  by  F.  Bascom.  Bull.  Geol.  Soc.  America, 
vol.  16,  1905,  pp.  289-328. 
22  Report  on  the  projected  survey  of  the  State  of  Maryland,  by  J.  T.  Ducatel 
and  J.  H.  Alexander.  Annapolis,  1834,  pp.  39.  See  also  Am.  Jour.  Sci.,  1st  ser., 
vol.  27,  1835,  pp.  1-38. 
23  Some  notices  of  the  geology  of  the  country  between  Baltimore  and  the  Ohio 
River,  with  a  section  illustrating  the  superposition  of  the  rocks,  by  Dr.  William 
E.  A.  Aikin.     Am.  Jour.  Sci.,  1st  ser.,  vol.  26,  1834,  pp.  219-232. 
21  Annual  report  of  the  geologist  of  Maryland,  by  J.  T.  Ducatel,  1839,  pp.  33. 
