﻿404 
  PKOCEEDINGS 
  OP 
  THE 
  CALIFORNIA 
  

  

  are 
  known. 
  It 
  is 
  impossible 
  to 
  reconcile 
  this 
  with 
  the 
  existence 
  of 
  even 
  four 
  

   months' 
  night 
  which 
  we 
  know 
  must 
  prevail 
  so 
  near 
  the 
  pole, 
  even 
  if 
  the 
  climate 
  

   there 
  were 
  tropical. 
  We 
  are 
  forced 
  to 
  the 
  conclusion, 
  in 
  spite 
  of 
  astronomical 
  

   opinions, 
  that 
  the 
  poles 
  have 
  changed 
  since 
  then, 
  and 
  this 
  may 
  help 
  to 
  explain 
  

   many 
  geological 
  puzzles 
  both 
  in 
  California 
  and 
  elsewhere. 
  Among 
  these 
  the 
  

   supposed 
  absence 
  of 
  all 
  eocene 
  animal 
  or 
  vegetable 
  remains 
  on 
  this 
  Coast 
  is 
  

   one 
  which 
  might 
  be 
  accounted 
  for 
  by 
  supposing 
  that 
  in 
  that 
  epoch 
  California 
  

   was 
  under 
  covering 
  of 
  polar 
  ice 
  ! 
  Such 
  a 
  theory, 
  though 
  it 
  may 
  be 
  called 
  ab- 
  

   surd 
  on 
  account 
  of 
  the 
  present 
  flattening 
  of 
  the 
  poles 
  by 
  centrifugal 
  force, 
  is 
  as 
  

   tenable 
  as 
  that 
  of 
  the 
  well-known 
  alternations 
  of 
  deep 
  ocean 
  and 
  dry 
  land 
  which 
  

   geology 
  proves 
  to 
  have 
  occurred 
  on 
  our 
  continent. 
  I 
  may 
  mention 
  in 
  this 
  con- 
  

   nection, 
  that 
  Prof. 
  Dana, 
  during 
  his 
  explorations 
  of 
  the 
  Oceanic 
  Archipelago, 
  

   saw 
  reasons 
  to 
  believe 
  that 
  it 
  has 
  been 
  slowly 
  subsiding 
  from 
  the 
  condition 
  of 
  

   a 
  continent 
  in 
  the 
  tertiary 
  and 
  recent 
  ages, 
  while 
  this 
  Coast 
  has 
  been 
  rising. 
  

   Thus, 
  alternations 
  of 
  land 
  and 
  ocean 
  have 
  doubtless 
  been 
  going 
  on, 
  usually 
  slow 
  

   and 
  gradual, 
  since 
  the 
  creation 
  of 
  the 
  world. 
  The 
  changes 
  in 
  fauna 
  and 
  flora, 
  

   which 
  in 
  our 
  limited 
  field 
  of 
  view 
  seem 
  to 
  have 
  been 
  sudden 
  and 
  convulsive, 
  

   were 
  probably 
  nearly 
  all 
  through 
  the 
  tertiary, 
  as 
  slow 
  as 
  at 
  present, 
  but 
  from 
  

   these 
  enormous 
  undulations 
  of 
  the 
  earth's 
  surface, 
  half 
  of 
  their 
  history 
  is 
  for 
  us 
  

   buried 
  beneath 
  a 
  fathomless 
  abyss. 
  

  

  Would 
  changes 
  of 
  the 
  poles 
  be 
  any 
  more 
  won 
  derful 
  or 
  impossible 
  ? 
  

  

  Observations 
  on 
  the 
  Genus 
  Caprella, 
  and 
  Description 
  of 
  a 
  New 
  

   Species. 
  

  

  BY 
  W. 
  N. 
  LOCKINGTON. 
  

  

  Among 
  the 
  Tetradecapoda, 
  or 
  fourteen-legged 
  crustaceans, 
  the 
  best 
  known 
  

   forms 
  of 
  which 
  are 
  the 
  pill-bugs, 
  wood-lice, 
  and 
  sand-hoppers, 
  there 
  is 
  no 
  more 
  

   remarkable 
  genus 
  than 
  Caprella. 
  The 
  abdomen 
  is 
  obsolete, 
  or 
  so 
  nearly 
  so 
  

   as 
  only 
  to 
  be 
  distinguishable 
  by 
  a 
  most 
  careful 
  examination 
  ; 
  and 
  the 
  entire 
  

   body 
  consists 
  of 
  the 
  seven 
  thoracic 
  segments, 
  each 
  of 
  which 
  is 
  exceedingly 
  

   attenuated, 
  so 
  that 
  the 
  creature 
  resembles, 
  in 
  its 
  general 
  appearance, 
  a 
  long, 
  

   slender 
  cater])illar 
  more 
  than 
  a 
  crustacean. 
  

  

  Although 
  classed 
  with 
  the 
  fourteen-legged 
  Crustacea, 
  the 
  Caprella:, 
  like 
  their 
  

   near 
  relatives, 
  the 
  Cyami, 
  or 
  whale-lice, 
  have 
  really 
  only 
  five 
  pairs 
  of 
  legs, 
  as 
  

   those 
  pairs 
  which 
  normally 
  spring 
  from 
  the 
  third 
  and 
  fourth 
  segments 
  are 
  

   absent, 
  their 
  place 
  being 
  filled, 
  in 
  the 
  males, 
  by 
  two 
  pairs 
  of 
  elongated 
  bran- 
  

   chias. 
  In 
  the 
  females 
  these 
  branchiae 
  are 
  modified 
  in 
  form 
  and 
  function, 
  becom- 
  

   ing 
  four 
  broad 
  plates, 
  which 
  fold 
  securely 
  over 
  each 
  other 
  on 
  the 
  lower 
  side 
  of 
  

   the 
  third 
  and 
  fourth 
  segments, 
  and 
  thus 
  composing 
  a 
  sac 
  or 
  pouch 
  in 
  which 
  the 
  

   eggs 
  and 
  immature 
  young 
  are 
  safely 
  carried. 
  

  

  The 
  comparatively 
  great 
  length 
  of 
  the 
  body 
  is 
  still 
  further 
  increased 
  by 
  the 
  

   long, 
  slender, 
  external 
  antennae, 
  and 
  the 
  backward 
  direction 
  of 
  the 
  hinderraost 
  

   legs; 
  and 
  the 
  resemblance 
  to 
  a 
  caterpillar 
  is 
  heightened 
  by 
  the 
  mode 
  of 
  pro- 
  

   gression, 
  which, 
  on 
  account 
  of 
  the 
  absence 
  of 
  legs 
  on 
  the 
  third 
  and 
  fourth 
  seg- 
  

  

  