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  GEOLOGY. 
  

  

  Zeuglodon 
  JlarJani, 
  from 
  the 
  yoke-like 
  form 
  of 
  the 
  teeth, 
  

   and 
  in 
  honor 
  of 
  Dr. 
  Harlan, 
  who 
  hrst 
  described 
  and 
  in- 
  

   troduced 
  it 
  to 
  the 
  notice 
  of 
  the 
  scientific 
  world. 
  

  

  The 
  original 
  name 
  is, 
  however, 
  retained 
  by 
  manj'^ 
  in 
  

   respect 
  to 
  the 
  rule 
  established 
  among 
  naturalists 
  which 
  

   regards 
  the 
  rights 
  of 
  priority 
  of 
  discovery. 
  

  

  It 
  has 
  also 
  been 
  named 
  the 
  Squalodon, 
  Phocodon, 
  and 
  

   the 
  Dorudon, 
  and 
  for 
  a 
  further 
  description 
  of 
  which 
  the 
  

   reader 
  is 
  referred 
  to 
  the 
  Monograph 
  of 
  Dr. 
  Robert 
  W. 
  

   Gibbes, 
  published 
  with 
  figures 
  in 
  the 
  first 
  volume 
  of 
  the 
  

   second 
  series 
  of 
  the 
  Journal 
  of 
  iJic 
  Academy 
  of 
  Natural 
  

   'Sciences, 
  Philadelphia. 
  

  

  In 
  Mississippi, 
  these 
  remains 
  occur 
  in 
  other 
  localities 
  

   than 
  those 
  mentioned. 
  The 
  detached 
  vertebra 
  have 
  

   been 
  found 
  in 
  the 
  City 
  of 
  Jackson, 
  and 
  the 
  immediate 
  

   vicinity, 
  at 
  Ball 
  Prairie, 
  about 
  six 
  miles 
  to 
  the 
  west 
  ; 
  

   and 
  in 
  Jones's 
  Prairie, 
  Section 
  15, 
  Township 
  9, 
  Range 
  

   4 
  E., 
  in 
  Madison 
  County. 
  

  

  Ill 
  Scott 
  and 
  Smith 
  Counties 
  they 
  are 
  frequentlj- 
  seen, 
  

   and 
  are 
  said 
  to 
  abound 
  in 
  Clark. 
  

  

  The 
  vertebra 
  and 
  ribs 
  are 
  obtained 
  in 
  nearly 
  a 
  perfect 
  

   state 
  ; 
  the 
  head, 
  being 
  composed 
  of 
  man}^ 
  separate 
  bones 
  

   or 
  plates 
  held 
  together 
  only 
  by 
  the 
  muscular 
  integument, 
  

   is 
  rarely 
  found 
  united, 
  and 
  but 
  few 
  perfect 
  teeth 
  have 
  

   been 
  obtained. 
  

  

  In 
  reference 
  to 
  their 
  variet}^, 
  their 
  unquestionable 
  

   foreign 
  origin, 
  and 
  the 
  changed 
  condition 
  from 
  an 
  origi- 
  

   nally 
  calcareous 
  material 
  to 
  the 
  diversilied 
  forms 
  of 
  sili- 
  

   iication 
  in 
  which 
  they 
  now 
  exist, 
  the 
  fossils 
  of 
  the 
  drift 
  

   compose 
  a 
  group 
  highly 
  interesting, 
  if 
  not 
  unique. 
  

  

  Of 
  this 
  metamorphosis, 
  or 
  conversion 
  of 
  lime 
  into 
  

   silex. 
  Dr. 
  Troost, 
  the 
  Geologist 
  of 
  Tennessee, 
  whose 
  loss 
  

   to 
  the 
  State 
  has 
  been 
  greatly 
  deplored, 
  remarks 
  : 
  ''• 
  This 
  

   change 
  in 
  the 
  chemical 
  nature 
  of 
  these 
  remains 
  is 
  cer- 
  

  

  