﻿354 
  BABCOCK: 
  NEW 
  ENGLAND 
  TURTLES. 
  

  

  Family 
  CHELYDRIDtE. 
  

  

  Chelydra 
  serpentina 
  (Linne). 
  

  

  Snapping 
  Turtle; 
  Snake 
  Tortoise; 
  Torup. 
  

  

  Plate 
  20. 
  

  

  Teshido 
  serpentina 
  Linne, 
  Syst. 
  Nat., 
  ed. 
  10, 
  1758, 
  vol. 
  1, 
  p. 
  199. 
  

  

  Chelydra 
  serpentina 
  Schweigger, 
  Arch. 
  Naturw. 
  Math., 
  Konigsberg, 
  1812, 
  vol. 
  1, 
  pt. 
  3, 
  p. 
  29.3. 
  

  

  The 
  Snapping 
  Turtle 
  is 
  the 
  largest 
  of 
  our 
  New 
  England 
  fresh-water 
  Chelonians. 
  

  

  Size. 
  — 
  Large 
  individuals 
  attain 
  a 
  total 
  length 
  of 
  about 
  three 
  feet. 
  Of 
  this 
  the 
  carapace 
  

   will 
  average 
  only 
  slightly 
  over 
  one-third 
  owing 
  to 
  the 
  very 
  long 
  neck 
  and 
  tail. 
  Such 
  a 
  turtle 
  

   will 
  weigh 
  about 
  fifty 
  pounds. 
  These 
  large 
  specimens, 
  however, 
  are 
  not 
  common. 
  Measure- 
  

   ments 
  of 
  the 
  shell 
  of 
  a 
  male 
  specimen 
  in 
  my 
  collection 
  are: 
  length 
  of 
  carapace, 
  12 
  inches; 
  width 
  

   of 
  carapace, 
  9l 
  inches; 
  length 
  of 
  plastron, 
  4^ 
  inches; 
  width 
  of 
  bridge, 
  2 
  inches, 
  tapering 
  to 
  

   I 
  of 
  an 
  inch 
  at 
  center. 
  A 
  mounted 
  specimen 
  in 
  the 
  collection 
  of 
  the 
  Boston 
  Society 
  of 
  Natural 
  

   History 
  vnth 
  a 
  carapace 
  length 
  of 
  14^ 
  inches, 
  shows 
  a 
  width 
  of 
  head 
  of 
  3| 
  inches. 
  

  

  Color. 
  — 
  The 
  carapace 
  and 
  upper 
  parts 
  varj^ 
  from 
  light 
  to 
  dark 
  brown, 
  sometimes 
  black. 
  

   The 
  carapace 
  is 
  often 
  covered 
  with 
  an 
  algal 
  growth, 
  which 
  gives 
  it 
  a 
  distinctly 
  greenish 
  tint. 
  

   The 
  plastron 
  and 
  under 
  parts 
  are 
  pale 
  yellow. 
  

  

  Description. 
  — 
  The 
  head 
  is 
  very 
  large 
  and 
  pointed. 
  The 
  upper 
  and 
  lower 
  jaws 
  terminate 
  

   in 
  strong 
  hooked 
  beaks. 
  Owing 
  to 
  the 
  low 
  arch 
  of 
  the 
  skull 
  the 
  eyes 
  are 
  placed 
  at 
  such 
  an 
  

   angle 
  that 
  the 
  range 
  of 
  vision 
  extends 
  upward 
  as 
  well 
  as 
  to 
  the 
  side. 
  The 
  neck, 
  which 
  is 
  cov- 
  

   ered 
  with 
  loose, 
  warty 
  skin, 
  is 
  of 
  such 
  length 
  that 
  the 
  head 
  can 
  not 
  be 
  completely 
  withdrawn 
  

   into 
  the 
  shell. 
  The 
  carapace 
  has 
  three 
  blunt, 
  irregular 
  keels, 
  very 
  pronounced 
  in 
  young 
  indi- 
  

   viduals, 
  but 
  which 
  gradually 
  disappear 
  with 
  age, 
  until 
  in 
  very 
  old 
  specimens 
  the 
  shell 
  is 
  quite 
  

   smooth.^ 
  It 
  is 
  sharply 
  serrated 
  posteriorly. 
  The 
  plastron 
  is 
  small 
  and 
  cruciform 
  in 
  shape, 
  

   thus 
  leaving 
  the 
  under 
  fleshy 
  parts 
  exposed. 
  The 
  tail 
  is 
  long 
  and 
  has 
  on 
  its 
  superior 
  surface 
  

   a 
  series 
  of 
  blunt 
  horny 
  crests. 
  There 
  are 
  also 
  two 
  smaller 
  lateral 
  rows. 
  The 
  under 
  surface 
  

   of 
  the 
  tail 
  is 
  covered 
  mth 
  large 
  shields. 
  The 
  feet 
  are 
  broad 
  and 
  webbed, 
  the 
  toes 
  being 
  pro- 
  

   vided 
  with 
  large 
  coarse 
  nails, 
  five 
  anteriorly 
  and 
  four 
  posteriorly.^ 
  

  

  Geographic 
  Distribution. 
  — 
  This 
  turtle 
  has 
  the 
  widest 
  range 
  of 
  any 
  fresh-water 
  Chelo- 
  

   nian 
  under 
  consideration. 
  It 
  extends 
  from 
  southern 
  Canada, 
  through 
  the 
  United 
  States 
  east 
  

   of 
  the 
  Rocky 
  Mountains, 
  into 
  Central 
  America. 
  

  

  ^ 
  H. 
  W. 
  Fowler 
  (1913) 
  describes 
  three 
  large 
  ones 
  in 
  the 
  Philadelphia 
  Aquarium 
  in 
  which 
  the 
  three 
  keels 
  on 
  the 
  cara- 
  

   pace 
  were 
  very 
  prominent 
  and 
  did 
  not 
  get 
  smoother. 
  

  

  ' 
  H. 
  Garman 
  (1892), 
  speaks 
  of 
  a 
  pair 
  "attached 
  side 
  by 
  side 
  for 
  most 
  of 
  their 
  lengths," 
  a 
  peculiar 
  malformation. 
  

  

  