﻿14 
  PROCEEDINGS 
  OF 
  THE 
  NATIONAL, 
  MUSEUM 
  vol.67 
  

  

  Chloephaga 
  leucoptera 
  has 
  a 
  very 
  curious 
  flat 
  tongue. 
  Ante- 
  

   riorly 
  there 
  is 
  a 
  single 
  row 
  of 
  very 
  weak 
  lateral 
  spines 
  or 
  hairs 
  

   which 
  a 
  little 
  further 
  back 
  develops 
  into 
  three 
  heavy 
  conical 
  tearing 
  

   " 
  teeth." 
  Posteriorly 
  it 
  ends 
  in 
  a 
  patch 
  of 
  small 
  spines. 
  This 
  is, 
  

   so 
  far 
  as 
  has 
  been 
  seen, 
  the 
  simplest 
  form 
  found 
  in 
  the 
  family. 
  

  

  The 
  swans 
  have 
  the 
  typical 
  structure 
  found 
  in 
  the 
  family, 
  which 
  

   is 
  modified, 
  however, 
  by 
  having 
  heavy 
  tearing 
  " 
  teeth 
  " 
  along 
  the 
  

   edges 
  of 
  the 
  median 
  groove. 
  This 
  is 
  true 
  of 
  Gygnus 
  gibbus, 
  G. 
  

   buccinator, 
  and 
  C. 
  columbianus. 
  

  

  Coscoroba 
  coscoroba 
  has 
  a 
  very 
  heavy 
  organ, 
  but 
  the 
  edges 
  of 
  the 
  

   median 
  groove 
  are 
  smooth 
  without 
  corrified 
  processes. 
  

  

  Cereopsis 
  novae 
  hollandiae 
  has 
  a 
  most 
  aberrant 
  form 
  of 
  tongue. 
  

   Typically 
  there 
  is 
  a 
  very 
  weak 
  row 
  of 
  lateral 
  spines, 
  which 
  may 
  be 
  

   entirely 
  worn 
  away 
  as 
  in 
  the 
  specimen 
  illustrated 
  (fig. 
  35). 
  Pos- 
  

   teriorly 
  there 
  are 
  various 
  fleshy 
  processes 
  which 
  may 
  be 
  covered 
  with 
  

   weak 
  spines, 
  absent 
  in 
  the 
  one 
  figured 
  however. 
  

  

  The 
  number 
  of 
  lateral 
  "teeth" 
  vary 
  throughout 
  the 
  family 
  and 
  

   roughly 
  follows 
  subfamily 
  groups. 
  

  

  Thus 
  the 
  Fuligulinae 
  tend 
  to 
  have 
  from 
  three 
  to 
  five, 
  usually 
  four 
  

   on 
  each 
  side. 
  While 
  members 
  of 
  the 
  same 
  species 
  may 
  not 
  show 
  a 
  

   constant 
  number 
  the 
  variation 
  will 
  be 
  found 
  to 
  be 
  within 
  these 
  limits. 
  

   This 
  is 
  true 
  of 
  Oidemia, 
  C 
  ' 
  haritonetta, 
  Histrionicus, 
  Arctonetta, 
  

   Marila, 
  and 
  Erismatura 
  jamaicensis 
  (fig. 
  29). 
  

  

  On 
  the 
  other 
  hand 
  the 
  Anatinae 
  present 
  from 
  5 
  to 
  as 
  high 
  as 
  

   12 
  lateral 
  spines. 
  This 
  is 
  true 
  of 
  Dendrocygna, 
  Anas, 
  Dafila, 
  

   Poecilonetta, 
  Mareca, 
  Nettion, 
  and 
  Querquedula 
  cyanoptera 
  (fig. 
  9). 
  

   Spatula, 
  being 
  a 
  broad 
  and 
  long 
  tongued 
  form, 
  has 
  as 
  many 
  as 
  12 
  

   on 
  each 
  side. 
  

  

  Aix, 
  Plectropterus, 
  Cairina, 
  and 
  Dendronessa 
  average 
  four 
  to 
  the 
  

   side, 
  while 
  typically 
  this 
  group 
  is 
  marked 
  by 
  an 
  absence 
  of 
  cornifica- 
  

   tion 
  of 
  the 
  edges 
  of 
  the 
  median 
  groove. 
  

  

  Throughout 
  this 
  group 
  there 
  is 
  a 
  similarity 
  of 
  tongue 
  form 
  that 
  

   makes 
  each 
  one 
  recognizable 
  as 
  belonging 
  to 
  the 
  family 
  Anatidae. 
  

   The 
  modifications 
  that 
  exist 
  are 
  all 
  based 
  on 
  a 
  type 
  pattern 
  which 
  

   is 
  characterized 
  briefly 
  as 
  a 
  fleshy 
  organ 
  with 
  at 
  least 
  one, 
  and 
  

   usually 
  two, 
  rows 
  of 
  lateral 
  hairlike 
  processes, 
  a 
  few 
  or 
  all 
  of 
  which 
  

   may 
  be 
  agglutinated 
  to 
  form 
  solid 
  cornified 
  toothlike 
  projections. 
  

   In 
  these 
  instances 
  it 
  is 
  notable 
  that 
  dissimilarity 
  of 
  diet 
  has 
  not 
  

   destroyed 
  evidences 
  of 
  relationship. 
  Conversely, 
  similarity 
  of 
  diet 
  

   as 
  compared 
  with 
  unrelated 
  forms 
  outside 
  the 
  family 
  has 
  not 
  pro- 
  

   duced 
  similar 
  tongues. 
  As 
  instance 
  witness 
  on 
  the 
  one 
  hand 
  the 
  

   tongues 
  of 
  several 
  fish 
  eaters 
  — 
  mergansers, 
  loons, 
  and 
  grebes 
  — 
  and 
  

   on 
  the 
  other 
  the 
  ruddy 
  duck 
  with 
  its 
  diet 
  closely 
  following 
  that 
  of 
  

   the 
  American 
  coot, 
  and 
  yet 
  without 
  paralleling 
  it 
  in 
  tongue 
  pattern. 
  

  

  