﻿FIFTH 
  REPORT 
  OF 
  THE 
  DIRECTOR 
  I908 
  161 
  

  

  line 
  that 
  may 
  reach 
  many 
  miles. 
  These 
  lake 
  excavations 
  caused 
  

   by 
  wave 
  and 
  undertow 
  are 
  not 
  only 
  smaller 
  and 
  more 
  shal- 
  

   low 
  than 
  stream 
  potholes 
  but 
  are 
  cut 
  at 
  the 
  same 
  level 
  on 
  a 
  line 
  

   surrounding 
  a 
  large 
  territory 
  and 
  any 
  higher 
  linear 
  series 
  

   would 
  be 
  indicative 
  not 
  of 
  the 
  phenomena 
  of 
  former 
  stream 
  ac- 
  

   tion, 
  rapids 
  or 
  falls, 
  but 
  of 
  former 
  wave 
  action. 
  A 
  new 
  term 
  

   for 
  these 
  shore 
  line 
  excavations 
  would 
  be 
  conducive 
  to 
  clear 
  think- 
  

   ing 
  and 
  on 
  account 
  of 
  their 
  difference 
  in 
  diameter, 
  depth, 
  position, 
  

   arrangement, 
  locality 
  and 
  manner 
  of 
  formation, 
  a 
  new 
  term 
  is 
  

   certainly 
  due 
  them. 
  The 
  name 
  cupJioles 
  is 
  proposed 
  and 
  will 
  be 
  

   used 
  hereafter. 
  

  

  That 
  these 
  cupholes 
  are 
  due 
  in 
  great 
  measure 
  to 
  vortexes 
  in 
  the 
  

   undertow 
  from 
  wave 
  action 
  is 
  shown 
  by 
  plate 
  5, 
  which 
  presents 
  

   a 
  view 
  of 
  the 
  seaward 
  end 
  of 
  the 
  glaciated 
  rock 
  boss 
  in 
  

   part 
  showm 
  in 
  plate 
  3. 
  The 
  cupholes 
  are 
  arranged 
  in 
  curving 
  

   lines 
  which 
  all 
  run 
  from 
  the 
  central 
  ridge 
  of 
  the 
  rock 
  mound 
  and 
  

   take 
  the 
  lines 
  of 
  the 
  undertow. 
  Many 
  cupholes 
  may 
  be 
  seen 
  to 
  

   have 
  become 
  confluent 
  and 
  the 
  figure 
  makes 
  a 
  very 
  interesting 
  

   study. 
  The 
  absence 
  of 
  pebbles 
  is 
  shown, 
  as 
  is 
  also 
  the 
  presence 
  

   of 
  minor 
  cupholes 
  within 
  the 
  major. 
  

  

  Just 
  under 
  the 
  edge 
  of 
  the 
  water 
  all 
  the 
  cupholes 
  have 
  become 
  

   confluent 
  and 
  the 
  result 
  is 
  a 
  distinct 
  shelf, 
  about 
  a 
  foot 
  wide, 
  cut 
  

   completely 
  around 
  a 
  more 
  exposed 
  portion 
  of 
  this 
  glaciated 
  boss. 
  

   Just 
  outside 
  the 
  edge 
  of 
  the 
  shelf 
  is 
  a 
  fine 
  clay 
  bottom 
  from 
  

   which 
  the 
  action 
  of 
  the 
  present 
  low 
  water 
  has 
  removed 
  some 
  few 
  

   centimeters 
  and 
  cut 
  the 
  surface 
  into 
  a 
  very 
  irregular 
  pattern 
  in- 
  

   dicative 
  of 
  varying 
  density. 
  Whether 
  or 
  not 
  Lake 
  Champlain 
  is 
  

   repeating 
  a 
  former 
  process 
  and 
  removing 
  some 
  of 
  its 
  own 
  sedi- 
  

   ment 
  or 
  whether 
  the 
  low 
  water 
  is 
  removing 
  the 
  sediment 
  of 
  the 
  

   Hochelagan 
  sea, 
  where 
  it 
  covers 
  the 
  till, 
  is 
  not 
  at 
  all 
  certain; 
  but 
  

   the 
  distinct 
  rock 
  shelf 
  cut 
  by 
  the 
  cupholes 
  w^ould 
  indicate 
  that 
  

   Lake 
  Champlain 
  had 
  never 
  cut 
  lower. 
  

  

  These 
  cupholes 
  may 
  be 
  found 
  around 
  the 
  entire 
  island 
  and 
  ex- 
  

   tending 
  deepest 
  where 
  the 
  undertow 
  is 
  greatest. 
  There 
  is 
  no 
  

   higher 
  line 
  shown 
  on 
  the 
  island 
  and 
  the 
  retreating 
  Hochelagan 
  

   sea 
  found 
  no 
  resting 
  place 
  until 
  the 
  waters 
  were 
  freshened 
  by 
  the 
  

   stream 
  inflow 
  and 
  the 
  lake 
  reached 
  the 
  present 
  comparatively 
  

   stable 
  level. 
  

  

  The 
  figures 
  given 
  show 
  in 
  each 
  case 
  glaciated 
  surfaces 
  run- 
  

   ning 
  from 
  above 
  high 
  water 
  mark 
  to 
  below 
  low 
  water 
  mark. 
  

   This 
  feature 
  is 
  present 
  to 
  a 
  greater 
  or 
  less 
  degree 
  on 
  every 
  

  

  