﻿652 
  

  

  PR0CEEDI^^08 
  OF 
  THE 
  NATIONAL 
  MUSEUM. 
  

  

  has 
  been 
  created 
  as 
  to 
  their 
  proper 
  association 
  with 
  the 
  skeleton 
  to 
  

   which 
  they 
  were 
  supposed 
  to 
  belong. 
  Abel, 
  in 
  an 
  article 
  published 
  in 
  

   1906/ 
  contended 
  that 
  these 
  bones 
  were 
  the 
  corocoids 
  of 
  a 
  large 
  bird 
  to 
  

   which 
  he 
  gave 
  the 
  name 
  Alabamornis 
  gigantea. 
  A 
  careful 
  restudy 
  of 
  

   these 
  elements, 
  however, 
  leaves 
  no 
  doubt 
  

   as 
  to 
  their 
  mammalian 
  characteristics 
  and 
  

   no 
  reason 
  to 
  assume 
  that 
  they 
  do 
  not 
  prop- 
  

   erly 
  belong 
  to 
  the 
  skeleton 
  with 
  which 
  they 
  

   were 
  found 
  associated. 
  While 
  they 
  evince 
  

   an 
  extremely 
  atropliied 
  state, 
  the 
  aceta- 
  

   bulum 
  plainly 
  retains 
  traces 
  of 
  the 
  cotjdoid 
  

   notch 
  and 
  the 
  pit 
  for 
  the 
  attachment 
  of 
  

   the 
  ligamentum 
  teres 
  (see 
  fig. 
  2, 
  p. 
  652), 
  

   while 
  the 
  bone 
  is 
  considerably 
  thickened 
  in 
  

   this 
  region. 
  Also, 
  the 
  prox- 
  

   imal 
  end 
  of 
  the 
  femur 
  (see 
  

   fig. 
  3, 
  p. 
  652) 
  shows 
  evidence 
  

   of 
  having 
  been 
  capped 
  with 
  

   an 
  epiphysis. 
  Not 
  having 
  

   the 
  actual 
  bones 
  to 
  exam- 
  

   ine 
  Abel 
  doubtless 
  was 
  led 
  // 
  

   to 
  a 
  wrong 
  interpretation 
  

   of 
  the 
  plates 
  published 
  b}" 
  

   Lucas, 
  because 
  they 
  do 
  

   not 
  show 
  very 
  clearly 
  the 
  

   essential 
  characters 
  of 
  the 
  

   bones. 
  This 
  is 
  due 
  to 
  the 
  

   fact 
  that 
  the 
  bone 
  surfaces 
  

   are 
  pitted 
  and 
  roughened 
  

   through 
  imperfect 
  preser- 
  

  

  FiG. 
  2.— 
  Pelvic 
  bone 
  of 
  American 
  

   Zeuglodon. 
  J 
  natural 
  size. 
  

  

  vation 
  and 
  the 
  reproduc- 
  

   tions, 
  which 
  are 
  from 
  pho- 
  

   tographs, 
  are 
  perhaps 
  somewhat 
  confusing. 
  

  

  The 
  anterior 
  portion 
  of 
  the 
  vertebral 
  column, 
  in- 
  

   cluding 
  the 
  cervicals 
  and 
  first 
  seven 
  thoracics, 
  are 
  

   not 
  highly 
  specialized 
  and 
  are 
  typically 
  mammalian 
  

   in 
  character. 
  But 
  from 
  this 
  point 
  backward 
  to 
  the 
  

   first 
  lumbars,.the 
  vertebrae 
  rapidly 
  gaining 
  in 
  size 
  

   and 
  increased 
  length 
  of 
  their 
  centra, 
  show 
  a 
  degree 
  

   of 
  specialization 
  that 
  is 
  unique. 
  The 
  vertebrae 
  from 
  the 
  beginning 
  

   of 
  the 
  lumbar 
  region 
  to 
  about 
  the 
  ninth 
  from 
  the 
  end 
  of 
  the 
  

   tail 
  have 
  exceedmgly 
  long, 
  heavy 
  centra 
  and 
  relatively 
  small 
  neural 
  

   arches, 
  and 
  are 
  comparatively 
  uniform 
  in 
  size 
  and 
  general 
  appear- 
  

  

  FiG. 
  3.— 
  Femur 
  of 
  

   American 
  Zeu- 
  

   glodon. 
  I 
  natu- 
  

   ral 
  SIZE. 
  

  

  •Centralbl. 
  Min. 
  Geol. 
  Palcont., 
  p. 
  4,56. 
  

  

  