FOE    THE    YEARS    1901-1905,   INCLUSIVE.  317 
Spinks  (Charles  H.). 
1.  Magnetite  and  its  uses. 
Cal.  Jour.  Teehn.,  vol.  4,  pp.  68-71,  1904. 
Describes  the  occurrence  and  geologic  relations  of  magnesite  deposits  in  southern  California, 
and  discusses  their  origin. 
Springer  (Ada). 
1.  On  some  living  and  fossil  snails  of  the  genus  Physa,  found  at  Las  Vegas,  New 
Mexico. 
Phila.  Acad.  Nat.  Sci.,  Proc,  vol.  54,  pp.  513-516,  1  pi.,  2 figs.,  1902. 
Springer  (Frank). 
1.  Uintacrinus:  its  structure  and  relations. 
Harvard  Coll.,  Mus.  Comp.  Zool.,  Mem.,  vol.  25,  no.  1,  pp.  1-89,  8  pis.,  1901. 
Describes  occurrence,  structure,  and  relations  of  this  crinoid  from  Cretaceous  strata. 
2.  On  the  crinoid  genera  Sagenocrinus,  Forbesiocrinus,  and  allied  forms. 
Am.  Geol.,  vol.  30,  pp.  88-97,  1  fig.,  1902. 
Includes  description  of  a  new  species  of  Sagenocrinus. 
3.  Cleiocrinus. 
Harvard  Coll.,  Mus.  Comp.  Zool.,  Mem.,  vol.  25,  no.  2,  pp.  93-114,  1  pi.,  1905. 
Spurr  (Josiah  Edward). 
1.  Origin  and  structure  of  the  Basin  ranges. 
Geol.  Soc.  Am.,  Bull.,  vol.  12,  pp.  217-270,  6  pis.,  1901.     Abstract:  Science,  new  ser.,  vol.  13,  p. 
98,  1901. 
Describes  the  structural  features  of  the  ranges  in  the  Great  Basin  region  and  discusses  their 
origin. 
2.  Variations  of  texture  in  certain  Tertiary  igneous  rocks  of  the  Great  Basin. 
Jour.  Geol.,  vol.  9,  pp.  586-606,  1  fig,,  1901. 
Describes  the  character  and  occurrence  of  the  variations  of  certain  andesitic  and  rhyolitic 
rocks  and  gives  chemical  analyses. 
3.  The  ore  deposits  of  Monte  Cristo,  Washington. 
U.  S.  Geol.  Surv.,  22d  Ann.  Rept.,  pt.  2,  pp.  777-865,  4  pis.,  42  figs..  1901.     Abstract:  Eng.  &  Mg. 
Jour.,  vol.  74,  pp.  240-241,  4  figs.,  1902. 
Describes  petrology,  general  geologic  relations  and  structure  of  the  area,  and  character, 
occurrence  and  origin  of  the  ores. 
4.  Application  of  geology  to  mining. 
Mg.  &  Sci.  Press.,  vol.  85,  pp.  145-146,  1902. 
Discusses  relations  of  geology  and  mining. 
5.  The  original  source  of  the  Lake  Superior  iron  ores. 
Am.  Geol.,  vol.  29,  pp.  335-349,  1902. 
Describes  the  origin  of  these  ores  as  being  derived  from  a  sedimentary  rock  containing  large 
quantities  of  glauconite. 
6.  Descriptive  geology  of  Nevada  south  of  the  Fortieth  Parallel  and  adjacent  portions 
of  California. 
U.  S.  Geol.,  Surv.,  Bull.  no.  208,  229  pp.,  8  pis.,  25  figs.,  1903. 
Describes  physiographic  features,  character  and  occurrence  of  sedimentary  and  igneous  rocks 
and  ore  deposits  and  structure  of  the  region,  including  resume  of  previous  publications  and 
unpublished  data  furnished  by  C.  D.  Walcott,  H.  W.  Turner,  F.  B.  Weeks,  R.  B.  Rowe,  G.  H. 
Girty,  and  E.  O.  Ulrich. 
7.  The  determination  of  the  feldspars  in  thin  section. 
Am.  Geol.,  vol.  31,  pp.  376-383,  1903. 
8.  Ore  deposits  of  Tonopah  and  neighboring  districts,  Nevada. 
U.  S.  Geol.  Surv.,  Bull.  no.  213,  pp.  81-87,  1903. 
Describes  the  history  of  the  development  of  the  field,  the  topography,  general  geology,  and 
character  and  occurrence  of  the  ore  deposits. 
