50  PRE-CAMBRIAN   ROCKS    OF    NORTH    AMERICA.  [bull.  86. 
31  Geological  and  Mineralogical  Observations  on  the  Northwest  portion  of  Lake 
Huron,  John  J.  Bigsby.   Am.  Jour.  Sci.,  1st  ser.,  vol.  in,  1821,  pp.  245-272. 
32  Report  on  the  District  lying  in  a  general  line  from  Georgian  Bay  on  Lake  Huron, 
and  the  lower  extremity  of  Lake  Erie,  Alexander  Murray.  Rept.  of  Prog.  Geol.  Sur- 
vey of  Canada  for  1842-'43,  pp.  16-17. 
33  Report  of  W.  E.  Logan.     Rept.  of  Prog.  Geol.  Survey  of  Canada  for  1845-'46,  pp.  98. 
34  Report  of  Observations  made  in  the  Survey  of  the  Upper  Peninsula  of  Michigan, 
John  Locke.    Executive  Docs.,  1st  sess.  30th  Cong.,  No.  2,  vol.  II,  1847-,48,  pp.  183-199. 
35  Report  of  an  Exploration  of  Several  Points  on  the  St.  Marys  River,  William  F. 
Channing.     Ibid.,  pp.  199-209. 
30  On  the  North  Coast  of  Lake  Huron,  Alexander  Murray.  Rept.  of  Prog.  Geol.  Sur- 
vey of  Canada  for  1847-'48,  pp.  93-124, 
37  Report  of  the  Geological  Survey  of  Canada  on  the  North  Shore  of  Lake  Huron, 
W.  E.  Logan,  1849,  pp.  8-20. 
33  On  the  Geology  of  parts  of  the  Coast  of  Lake  Huron,  the  Spanish  River,  etc.,  Alex- 
ander Murray.     Rept.  of  Prog.  Geol.  Survey  of  Canada  for  1848-'49,  pp.  7-46. 
39  On  the  Footprints  occurring  in  the  Potsdam  Sandstone  of  Canada,  W.  E.  Logan* 
Quart.  Jour.  Geol.  Soc,  London,  vol.  vni,  1852,  pp.  199-213;  with  a  geological  map. 
40  Remarks  relating  chiefly  to  the  succeeding  Reports,  W.  E.  Logan.  Rept.  of  Prog. 
Geol.  Survey  of  Canada  for  1857,  pp.  1-12. 
41  On  the  Coast  at  the  mouth  of  French  River,  Georgian  Bay ;  on  Echo  Lake  and  its 
environs,  and  on  the  Limestone  of  Bruce  Mines,  Alexander  Murray.  Ibid.,  pp.  13-27; 
accompanied  by  a  map. 
42  On  the  Division  of  the  Azoic  rocks  of  Canada  into  Huronian  and  Laurentian,  Six 
William  E.  Logan.     Proc.  Am.  Assoc.  Adv.  Sci.,  11th  meeting,  part  2,  1857,  pp.  44-47 J 
43  On  the  Country  between  the  Thessalon  River  and  Lake  Huron,  and  between  the 
Thessalon  and  Mississagui,  Alexander  Murray.  Rept.  of  Prog.  Geol.  Survey  of  Canada 
for  1858,  pp.  67-100;  accompanied  by  a  map  and  section. 
44  On  the  Cambrian  and  Huronian  Formations,  J.  J.  Bigsby.  Quart.  Jour.  Geol.  Soc, 
London,  vol.  xix,  1863,  pp.  36-52. 
45  On  the  Occurrence  of  Organic  Remains  in  the  Laurentian  rocks  of  Canada,  Sir  W. 
E.  Logan.     Quart.  Jour.  Geol.  Soc,  London,  vol.  xxi,  1865,  pp.  45-50. 
46  Is  there  a  Huronian  Group?  R.D.Irving.  Am.  Jour.  Sci.,  3d  ser.,  vol.  xxxiv, 
1887,  pp.  204-216,  249-263,  366-374. 
47  The  Original  Huronian,  N.  H.  Wiuchell.  16th  Ann.  Rept.  Geol.  and  Nat.  Hist. 
Survey  of  Minn,  for  1887,  pp.  12-40. 
48  Observations  in -the  Typical  Huronian  Region  of  Canada,  Alexander  Winchell. 
Ibid,  pp.  145-171. 
49  Notes  on  a  part  of  the  Huronian  Series  in  the  Neighborhood  of  Sudbury  (Canada), 
T.  G.  Bonney.     Quart.  Jour.  Geol.  Soc,  London,  vol.  xliv,  1888,  pp.  32-45. 
50  On  the  Contact  of  the  Huronian  and  Laurentian  rocks  North  of  Lake  Huron,  Al-] 
fred  E.  Barlow.    Am.  Geol.,  vol.  vi,  1890,  pp.  19-32. 
51  The  Origin  of  Gneiss  and  some  other  Primitive  rocks,  Robert  Bell.  Proc.  Am:i 
Assoc.  Adv.  Sci.,  1889,  38th  meeting,  pp.  227-231. 
52  Recent  Observations  on  some  Canadian  rocks,  Alexander  Winchell.  Am.  Geol., 
vol.  vi,  1890,  pp.  360-370. 
53  A  Last  Word  with  the  Huronian,  Alexander  Winchell.  Bull.  Geol.  Soc.  America, 
vol.  ii,  1891,  pp.  85-124. 
54  The  Nickel  and  Copper  Deposits  of  Sudbury  District,  Canada,  Robert  Bell.  Ibid., 
pp.  125-137. 
^Further  observations  on  the  Typical  Huronian,  and  on  the  rocks  about  Sudbury,, 
Ontario.     18th  Ann.  Rept.  Geol.  and  Nat.  Hist,  Survey  of  Minn,  for  1889,  pp.  47-59. 
56  Observations  upon  the  Structural  Relations  of  the  Upper  Huronian,  Lower  Hiiro-1- 
nian  and  Basement  Complex  on  the  North  Shore  of  Lake  Huron,  Raphael  Pumpclly 
and  C.  R.  Van  Hise.    Am.  Jour.  Sci.,  3d  ser.,  vol.  xliii,  1892,  pp.  224-232. 
